This is the implication that a character who dislikes a particular thing is secretly a practitioner of that thing.
This especially comes into play when ethnicity or homosexuality is involved. Such a character is likely to believe in negative stereotypes about his own group (no matter how irrational), and hate himself for it, or live by those stereotypes so they become self-fulfilling prophecies. If Fantastic Racism is in play, such as with Differently Powered Individuals, the person may try to suppress the trait that makes them part of the hated group, or use said power as a weapon against them.
In older shows this sometimes comes up with racist characters who are exposed as being light-skinned African-Americans who are 'passing'. Depending on the time frame of the media, the result may be either to show that the character should love himself or, in very old media from before 1940 or so, to show that the character is a sneaky liar who wasn't ethical enough to accept his "natural" place in the order of things.
This sort of implication is "non-falsifiable": If even denial is taken as proof, there's no way to prove innocence. Characters who don't actually fall under this trope, but are accused of it by other characters, may get increasingly angry (or despondent) about no one believing them.
This trope comes in several flavors.
The hater genuinely does not know he is a member of the group he hates.
The hater has clear evidence that he is a member of the hated group but is in denial. He refuses to identify with said group and often comes up with convoluted explanations as to why he isn't actually a member. Will often invoke the No True Scotsman fallacy.
The hater privately accepts that he is a member of the hated group but hides it from others.
The hater hates all members of the group, including or especially themselves.
In one chapter of Ai Kora, Maeda attracts the attention of Sajima, a Sadist Teacher who seems to have it out for him because of his "parts love". Turns out Sajima is a parts fetishist himself, but because of this, he was once in a student-teacher love affair that ended in tragedy, and he doesn't want something like that happening to Maeda.
One of the more interesting elements lost in the adaptation of Go Lion to the series Voltron is that Prince Sincline is not only the son of a human woman whom his father later disposed of, but that this woman was a citizen of Planet Altea, where his worst enemy lives. His reaction: kill his own grandmother Honerva.
Yu-Gi-Oh!: Seto Kaiba loathes his adoptive/stepfather and yet, because of the nightmarish training he underwent, he actually became the man who ruined his childhood. While he's not as bad as him, his methods and actions are rather questionable.
In Samurai Usagi (not to be confused with Usagi Yojimbo) a group of samurai-hating/murdering ronin all come from samurai families so they know first-hand how horrible samurai can be. To their consternation they're matched with the Usagi Dojo, who really clash with how they imagine samurai to be.
Neji of Naruto repeatedly put down Naruto and Hinata for trying to escape their "fate" to be weak. During their fight, Naruto pointed out that despite everything he said Neji was still struggling against his own fate as a member of the Branch Family.
In Soul Eater Having spent the series' early arcs rejecting any connection between himself, his father, and bad guys like Asura and Eibon, Death the Kid does not react well to the revelation that he and they are the same; Eldritch/Humanoid Abominations
Graydon Creed, the founder of the anti-mutant Friends of Humanity in X-Men, is not himself a mutant — but his parents were Mystique and Sabretooth.
Larry Trask, son of Sentinel-maker Bolivar Trask. He very nearly succeeded in having his giant robots wipe out all (then-known) mutants, but when his dad's friend Judge Chalmers ripped the power-suppressing amulet off of him, surprise surpise, Larry's a mutant too.
A surprisingly large number of anti-mutant bigots from the X-Men's Rogues Gallery are cyborgs - including Donald Pierce, Akab, Cameron Hodge, Bastion and the Phalanx. So while they're not mutants, they're not exactly normal humans, either.
The villain Magneto is also an example. He hates Nazis for what they did to him and his family, but as a result became a mutant-supremacist, hating all humans and just becoming a different kind of bigot.
Major case of Depending on the Writer. He's dated humans, and he's gone way out of his way to protect them… but, yes, he's also tried to wipe them out. He's conflicted.
In the Ultimate Universe Magneto and all mutants are actually human beings, who have been genetically altered by an airborne variation of the super soldier serum.
The "homophobes are all secretly gay" idea shows up in a few comics, including Preacher and The Authority.
There is a theory that Rorschach was deeply closeted because of his apparent dislike for homosexuals (and women). See the WMG page for the graphic novel. Somewhat wobbly, since Rorschach dislikes all forms of sexuality.
Red Hulk is implied to be someone who really hates the Hulk. He turns out to be General Ross.
In Empowered, Mind???? takes a peek into (ex-)lover Spooky's memories and instantly grasps that her public persona has been subconsciously patterned after the same vain blonde bimbos she was so traumatized by. Both physically (sans actual Blondeness) and personality.] Said blonde bimbos even sold their souls for "supernatural hotness" (sans superpowers) just like Spooky did, and for the exact same reasons. Spooky discovered this when she tried to use her powers to take revenge — her patron demon didn't allow it because he is forbidden from interfering with other demons' clients.
In Irredeemable, The Survivor (briefly) helps defeat The Plutonian out of vengeance for killing his twin brother, and soon takes the spot of the world's most powerful hero. The power and reputation quickly corrupt him though, and he soon becomes just as petty and vindictive as the Plutonian was before he became evil. This includes feeling entitled to having Kaidan, who had picked his brother over him, and considering murdering his other brother so he could keep his top spot one The Plutonian comes back.
The Psyche Master in Empath: The Luckiest Smurf is a Smurf who hates his own blue-skinned race and creates a Caucasian-skinned race of people called the Psyches who are taught to hate Smurfs. Of course, none of the Psyches know what the Psyche Master really is.
Rika in the Touhou fanfic The Tale of Rumia hates Youkai with a blinding passion- and at the end of the arc she's introduced in, it's revealed that over the years, she herself became a Youkai. She never really stops being in denial about it, although she privately turns herself into a robot so that she won't have to live with the shame.
In the Pony POV Series, Nightmare Eclipse loathes Discord and seeks to punish him for his crimes. However, her methods of doing so ultimately not only make her worse than he is, but causing him to have a Heel Realization and her forcing him still doing the things she's punishing him just so she can keep punishing him, effectively meaning everything she hates him for is now her doing. [[spoiler:Rota Fortuna, the Alicorn of Fate, lampshades this by giving her a Breaking Lecture during the Nightmare's defeat.
Rota Fortuna]: You condemn Discord for the murder and sin he's done onto others, yet you use those same ponies to die and suffer for your satisfaction. He only continued to make the ponies suffer because you allowed and then forced him to do so. The very sins you claim to punish him for are now your own. You embarrass yourself!!
The main character of Inside A Skinhead / The Believer is viewing himself as a highly anti-semitic white supremacist, despite being of Jewish origin himself. Of course, he tries to hide his biggest secret but ultimately fails.
In American Beauty, the homophobic neighbor turns out to be a closeted homosexual.
Lampshaded in This Is England: one of the far-right extremist characters, Combo, is a racist played by a mixed-race actor... hence his Meaningful Name.
Brian from Monty Python's Life of Brian hates Romans only for his mother to reveal that he is half Roman. He hates them because they have invaded his homeland, not because they are Romans, though.
Erik/Magneto from X-Men: First Class hates Nazis due to being a survivor of the Holocaust, but ultimately embraces racism against non-mutants.
Enforced in the first X-Men film, where Magneto's crew mutates Senator Kelly, the US government's biggest backer of mutant suppression. Although we don't really get too good a gauge of how he feels about it, since he dies as a result not too long after.
In I, Robot, Detective Spooner (Will Smith) displays an intense dislike towards humanoid robots... despite being a cyborg. Although, he does have a justified Freudian Excuse for that one.
Surrogates features the Prophet, a man leading a group against the eponymous surrogates. It turns out that he himself is a surrogate, controlled by the inventions' creator at that.
In Die Hard with a Vengeance, the character of Zeus is a black man with serious problems with white people, most especially white racists. Eventually McClane calls him out on the fact that he's acting like a racist himself.
Subtly hinted at for comedy with Nigel Powers in Austin Powers: Goldmember: "There are only two things I can't stand in this world! People who are intolerant of other people's cultures... and the Dutch!"
In The Human Condition, Kaji openly states his moral disgust for deserters and POW escapees. He becomes both by the end of the film.
In Who Framed Roger Rabbit, Judge Doom turns out to be a Toon in a human mask. Possibly justified in that he was motivated by greed, not bigotry, although he makes several anti-Toon statements prior to The Reveal as well (claiming, for example, that Toons are naturally lawless and deserve the most brutal punishments imaginable). It's probable that he's saying those things not because he believes other toons are like that, but because he knows that HE is like that.
Chink is a movie about Eddy Tsai, a self-hating Asian who becomes a serial killer targeting other Asians. He changes his name to "Richards" and falsely claims to have been adopted by white parents.
Jay of the View Askewniverse often makes homophobic remarks, but it's been hinted he's secretly gay or at least bi.
The movie Thor spends much of its arc following the self-destruction of Loki, setting him up for his role as the villain of Avengers. His racism against Frost Giants clearly has deep roots, but was never a major part of his life until it turned out he was one. Along with being a "Well Done, Son" Guy who seems honestly to be The Unfavorite and regularly suffer All of the Other Reindeer, and with knowing he's actually responsible for Thor's exile and the fact that they're currently at war, and combined with unexpectedly being temporary king, this violent undermining of his entire identity causes him to go completely insane.
Insane actions taken include but are not limited to setting up a complex plot to allow him to 'heroically' kill his biological father in person and the attempted destruction of the Frost Giant home world. He attempts suicide at the end, but just comes back crazier.
Even though his father was a Muggle, Lord Voldemort, the Big Bad, believes in the supremacy of pure-blooded wizards and hates those with Muggle blood. Word of God states that Voldemort's own half-blood nature, coupled with his obsession with wizard blood purity, is based on perceptions of Hitler.
Severus Snape also counts as a minor example. In his youth, he hated James Potter and Sirius Black from Gryffindor because they were bullying jerks who relentlessly picked on the Slytherin-sorted Snape, who back then was a (relatively) nice guy in comparison. When they grew up into adults, however, the situation ironically became reversed: James Potter and Sirius Black grew up into nice adults, while Snape actually became the bully he hated in his youth, because Snape decided to retroactively get back at Gryffindor by abusing his position as a teacher to protect Slytherin from penalties and punish Gryffindor for lots of invented infractions.
In Deryni Rising, the first book of Katherine Kurtz's Deryni series, Queen Jehana loudly claims her hatred of all Deryni, and later on Morgan describes this very trope when confronting her to obtain her peaceful cooperation during her son Kelson's coronation. It turns out that she is, indeed, a full-blooded member of the magically gifted Deryni race. Thanks to Internalized Categorism, she becomes a Boomerang Bigot and spends several years in penance for the sins of being Deryni.
Seek ye the true reflecting pool? Look to the enemy you despise, not the friend you love.
Hinted at, though never explicitly stated, for one character in Those Who Walk in Darkness. Soledad joined MTac as a means of revenge on the super-villain Bloodlust, who destroyed her hometown. It's mentioned offhandedly that Bloodlust's "power" was his skill at inventing things, which he mostly used to design weapons. Soledad herself designs Abnormal Ammo, including but not limited to phosphorus bullets, poisoned bullets, explosive bullets, and homing bullets, all clearly beyond the skill of any other normal person in the setting.
In the Sword of Truth novel Blood of the Fold the leader of the eponymous organization (which despises all forms of magic), Tobias Brogan, turned out to be one of these. His sister had magic but he was not actually aware of his own abilities. The protagonist Richard Rahl is clearly able to recognize Brogan has the gift, confusing Brogan greatly during a discussion on defeating evil and the insidiousness of said evil, and telling him 'Be careful the shadow you chase is not the one you cast'. Brogan explicitly does not understand what Richard was hinting at.
In Witch Week, an alternate Earth on which witches are known, feared, and persecuted turns out to also be a world on which nearly every human is secretly a witch.
Shortly after having his new home destroyed, his father killed, and being forced on the run with his mother by the Harkonnen family, Paul points out to his mother that she is Baron Harkonnen's daughter, making them part of the very noble family that they despise.
Essentially directly stated in one of the epigraphical quotations at the beginning of a chapter:
"What do you despise? By this are you truly known."
from the Manual of Muad'dib by the Princess Irulan
In Kate Chopin's short story "Desiree's Baby", the slave-owner Armand rejects his wife Desiree and their newborn son due to the son's obvious African heritage. He takes this to be proof that Desiree is also of mixed heritage, and she eventually gets fed up and goes back home to her parents with her son in tow. While throwing out Desiree's things, Armand eventually comes across letters from his deceased mother that reveal that she was one of his father's former slaves.
Artemis Fowl:The Lost Colony has Leon Abbot, who has an intense hatred of warlocks for relying on magic over brute strength, despite the fact that he uses magic power he stole from a warlock to brainwash his kinsmen into loyal minions.
In the Lunar Chronicles Cinder expresses hate toward the Lunars, a race/species of people who live on the moon and have powers. It turns out that Cinder isn't just a Lunar, but that she's their princess.
In "The Shadow Over Innsmouth", the protagonist finds out that one of his ancestors is a Deep One, a fish-like monster. He eventually goes underwater to live with the other Deep Ones.
In "Facts Concerning the Late Arthur Jermyn," the title character goes insane and sets himself on fire upon realizing that one of his distant ancestors was an ape goddess.
In the July 28, 2010 episode of The Daily Show, Jason Jones interviewed Scott Lively, who argued that the Nazis persecuted gays to hide their sexuality:
Scott Lively: The Nazis did persecute homosexuals to distract public attention away from their homosexuality. Jones: So that which you hate the most... you secretly are. (Beat) Lively: I am not gay. Jones: I didn't say you were.
Hazel on Degrassi The Next Generation is rude to the Muslim girl on Culture Day and secretly pretends to be Jamaican, until the Muslim girl's exhibit is vandalized (context: this was only a few months after 9/11) and Hazel comes clean about her Somali heritage.
On Heroes, Angela vaguely hints that Danko, The Hunter of supers, might be a super himself. Whether this is true is left ambiguous.
Dave Karofsky on Glee is highly homophobic and bullies Kurt, and it's revealed in the second season that he's actually gay.
Dr. House harbors a simmering rage at stupid doctors and clueless patients. He's both; when doctors misdiagnosed his leg clot, House insisted on waiting it out instead of amputating. He ended up with 1˝ legs and double the pain.
Kutner acts pretty hostile towards a group of high school bullies. His co-workers immediately assume he was bullied in high school (as Taub theorizes, being an Indian-American and having had his parents murdered in front of him most likely didn't help his popularity). However at the end of the episode, we see Kutner visiting a former classmate and apologizing to him about bullying him. A rare positive example?
The season two finale of Murdoch Mysteries has a mild example. A visiting Mountie starts upstaging Murdoch in the areas where he usually excels which leads Murdoch to declare "I don't know how anyone could put up with it." As Murdoch walks off his superior says to a third character "Yet somehow I manage." Of course it also later turns out that Murdoch and the Mountie are half-brothers.
Jocelyn Jee Esien's sketch show featured the character of Fiona, a black woman who dislikes black people and fears they will "out" her to her white co-workers, who (she believes) do not know that she's really black.
The image above is from Chappelle's Show, which contains an extremely literal example; in the sketch "Clayton Bigsby, White Supremacist", it is revealed that, in a twist of irony, the eponymous blind Ku Klux Klan leader is actually black (and the only reason it has gone unnoticed is because to his robes and his friends hiding his own race from him). He later becomes a Boomerang Bigot in the closing narration:
In the past few weeks, Clayton Bigsby has finally accepted that he is a black man. And just three days ago, he filed for divorce from his wife. When asked why, after nineteen years of marriage, he replied, "Because she's a nigger lover".
Extremely southern Blanche from The Golden Girls discovers when attempting to join "The Daughters of the South" (an expy for "Daughters of the Confederacy") that not only is her great-grandmother a Yankee from Buffalo NY, but was nee Feldman.
In episode 7x01 of Supernatural, Castiel kills a homophobic preacher who Cas reveals is secretly gay himself.
Gordon Walker hated all supernatural creatures and thought that they should all be killed. After his Karmic Transformation into a vampire, he agrees to let his partner kill him, but not before using his enhanced abilities to try and kill Sam Winchester, who gained psychic powers after ingesting demon blood.
In one episode of Grimm, Nick suspected there was another Grimm killing wesen in Portland. It turned out to be another wesen who was in denial about what he was and was trying to kill all wesen. When he's forced to confront his true form, he starts saying to Nick "You should kill me!"
Leslie Knope from Parks and Recreation is very disdainful of people from Eagleton, a nearby affluent town. She later discovers she was born there.
The fifth season introduces Marcia Langman's husband Marshall. Like her, he's a right-wing Christian fundamentalist horrified by the slightest hint of sexual deviation. He's also very obviously Camp Gay.
Liz: Toofer's just afraid of black people. Tracy: Which one is Toofer? Liz: The black guy.
This is used to explain Rodrigo Borgia's treatment of his elder son Cesare, whom he spurns and ignores in favour of his bratty younger son Juan. While Cesare is certainly no saint, he is clearly the more dutiful and intelligent of the two, and Rodrigo's hostile attitude towards him sometimes seemed illogical, but he finally breaks down and admits that he sees too much of himself in Cesare, and therefore finds him far more difficult to love than his other children.
Helena from Orphan Black is a clone, but hates her sisters, believing herself to be the original from whom her sisters were cloned.
Pink Floyd's The Wall has the main character become the very thing his father had died fighting against, as noted in the later songs "In The Flesh", "Run Like Hell", and "Waiting For The Worms"...at least within his own mind. This is made even more noticeable in the movie version.
Titledropped in "Brush the Dust Away" by in Flames, "We think we're in control then we become the things we hate"
The video for "Sugar, We're Going Down" by Fall Out Boy, is about a teenager with antlers, whose girlfriend's dad despises the fact she's dating a boy with antlers. At the end, dad gets hit by a truck while trying to shoot the kid, and as Antler Boy rushes over to help, it's revealed the dad has deer hooves.
During a segment on WWE Raw, CM Punk taunted John Cena with the fact that he (and by extension, Cena's hometown of Boston, of which Raw was taking place in that night...) was no longer the underdog by consistently being the "top dog" in the WWE, stating that he was no longer the Boston Red Sox, but rather the New York Yankees. Naturally, Cena didn't take too kindly to the comparison and promptly decked Punk after his comments.
A campaign in the old Marvel RPG had a mutant villain wanting to eradicate all mutants, founding an American NASI party, and of course being mutant himself.
Emperor Karl Prosek in Rifts is rumored to be a magician.
In the Ravenloft setting, Malocchio Aderre seized political control of Invidia and initiated a pogrom against the Vistani. Malocchio's mother, whom he ousted from power, is part Vistani herself.
The general concept behind sanctioned psykers in Warhammer 40,000, who must wield the energies of the Warp to defend Humanity from, among other things, the creatures of said Warp.
The New World of Darkness sourcebook Second Sight explicitly states that possessors of the two anti-psychic merits listed are latent psychics who have mental blocks preventing them from accessing their powers, and that this in turn makes them virulently skeptical.
Paranoia is generally played with every player character as a "Troubleshooter" whose job is to hunt down various types of traitors, including unregistered mutants. Due to unacknowledged malfunctions in the cloning vats, everyone in the setting is a mutant. Bonus irony if they're also a member of the "Anti-Mutant" secret society, the members of which are completely unaware that there's not a single genetically pure human among them.
This trope is given something of a work-out in Fate/stay night, especially in the "Unlimited Blade Works" route: Archer is quite vocally disapproving of the idealism and stubbornness that seems to plague most of his 'allies' (especially Shirou), and yet it is repeatedly pointed out by several characters and scenes that he is, in many ways, just as bad when it comes to suffering from Chronic Hero Syndrome. Just to make things weirder, this is a LITERAL example in regards to Shirou, considering that they are the same person.
Grand Theft Auto IV gives us Bryce Dawkins, Deputy Mayor of Liberty City, notorious for his vitriolic homophobic rants (and advocacy of family values) to appease to his right-wing base... all the while having an affair with Bernie Crane, a famously Camp Gay fitness trainer and alter-ego of Florian Cravic, Niko Bellic's former comrade. Once their affair is leaked (as a postgame radio news indicates), blowing the closet open for the whole city to see, Dawkins apparently decides to enter rehab until the pressure has dissipated.
Adrian from X-Men: Destiny is a Purifier-in-training and despises mutants. Turns out he is one, though he had no way of knowing until the events of the game.
Bertrand from inFAMOUS 2 considers Conduits to be demons and ultimately wants them to be exterminated, but is secretly a Conduit himself. Although Cole points out that he most likely is jealous of the fact that whilst others became shiny supermen, he got to be a big bug. So maybe instead of "you are what you hate," he falls more under "you hate that others like you possess awesome powers yet yours suck."
In Hatoful Boyfriend, Sakuya, the proud heir of a pure-blood fantail noble family, treats every non-pureblood bird like trash, including even his half-brother Yuuya who he calls a "half-breed mongrel". However, he learns on the Bad Boys Love route that he's actually not the true heir of the Le Bel family and is Yuuya's full brother, which means that he's the very same "mongrel" that he constantly scorned Yuuya for being.
In one episode of SpongeBob SquarePants, Squidward claims he hates Krabby Patties, but after just having a tiny bite, he tries harder and harder to secretly get a Krabby Patty. He is finally caught in the Patty Vault. For clarification he hated them before he ate them because he's Squidward and he's a grump but after he ate one, he loved it but lied to everyone, including Spongebob who later finds Squidward eating thousands of Krabby Patties. Which go straight to his thighs. And then he blows up. (Run-on sentences without context are fun!)
Brian is a liberal who disapproves of racism but still instinctively barks at black men due to his upbringing.
In his defense, as a dog he has no control over it.
In an episode of American Dad!, Francine is revealed to dislike left-handed people thinking of them as "the devil's minions". It's also revealed that Francine herself is naturally left-handed and dislikes lefties due to being struck in the orphanage she was in as a child when using her left hand.
Cartman hates "Gingers" (People with red hair, freckles, and pale skin) and insists they have no soul. As revenge Stan, Kenny, and Kyle draw freckles on him and dye his hair red in the middle of the night. He then hangs out with the gingers and whips them into a genocidal frenzy against everyone else. At a massive rally, they're about to kill everyone who isn't a ginger (starting with the "Daywalker", Kyle) only to have Stan, Kyle, and Kenny reveal Cartman's not a ginger. Then he just goes back to ripping on gingers. And then in 201 it turns out Cartman's father was also Scott Tenorman's father, making Cartman half-ginger.
Mr Garrison is homophobic in the early seasons, and is in denial about his sexuality throughout seasons 1-3 until he admits to himself that he is gay in the fourth season. When his sex change results in Mister Slave breaking up with him, he goes back to being hateful to homosexual men, and when it turns out Mister Slave is going to marry Big Gay Al, Garrison becomes an angry opponent of gay marriage. Then there's a mini-arc where Mrs. Garrison thinks it's "wrong" to be with another woman, but enjoys it and claims to then be a lesbian... And then there's a reverse sex change and Garrison becomes a man again, and almost immediately uses a homosexual slur. There's a quote from one of the creators that goes something along the lines of, "Garrison just hates whatever he happens to be."
Uncle Ruckus from The Boondocks. He's the darkest guy in the series and he hates black people with a passion. He does his best to distance himself from being black, holding on to whatever European heritages he believes he has ( though a genetic test in one episode reveals he's 102% African, with a 2% margin of error) and claims to have a condition called "re-vitiligo", the "opposite of what Michael Jackson had", which supposedly causes him to get darker.
When Springfield tried to pass a law deporting all immigrants in The Simpsons, Moe was one of its most vocal supporters. He viciously blames them for everything that ever happened in town, including bear attacks, and rants about things that piss him off about them like not learning the local language. He was later spotted nervously taking the citizenship exam wearing a very thin disguise.
In an episode of Futurama where Bender and Amy had a robosexual relationship, Bender at one point was sent to a retreat where Preacherbot urged sinners to wrestle with human mannequins in order to symbolically beat out their sinful impulses. Naturally, this entailed the robots making out with the mannequins. Preacherbot was clearly aroused.
In Justice League, General Eiling deeply despises superheroes and metahumans. When his organisation Cadmus was disbanded, he decided to use a superhuman serum and turn himself into "The General" to fight the Justice League, facing the League's non-metahuman members. The public calls him out on his actions.
Personally hangs a lampshade on it and says it almost word for word but claims he is still in the right.
In Recess, Spinelli despises "The Ashleys" (a group of Alpha Bitch-esque girls all named Ashley) yet becomes very defensive when it's pointed out that her own first name is Ashley, since she despises the thought of being lumped in with them.
In psychoanalytic theory, reaction formation is where one tries to deal with anxiety-causing impulses by overemphasising the opposite, going against their own desires by fervently acting against them. In other words, this.
Author Norman Finkelstein has often been described by others as a self-hating Jew. Which has its own rather unfortunate implications, as all he does is criticize Israel's brutal policies against the Palestinians. He also published a book noting how the Holocaust is used to silence critics of Israel and bring in undue sympathy to a state engaging in heinous crimes against humanity itself. He's also the son of Holocaust survivors, but that did not stop his critics.
Adolf Hitler himself has been accused of having Jewish and even African ancestry based on DNA evidence.
The Jewish claim comes from the fact that Adolf Hitler's paternal grandfather was probably Johann Georg Hiedler, but since Alois Hitler, Adolf's father, was a bastard, it is difficult to discern who the Fuhrer's grandfather actually was. There is a probably untrue claim that Adolf Hitler's grandfather was a Leopold Frankenberger, a Jewish man whom Adolf's grandmother was working for. The Fuhrer himself made sure to have extensive SS investigations into the situation, and unsurprisingly, his loyal bodyguards found that his racial background was entirely Austrian German.
There was also Emil Maurice, founder of the SS, who was found to have Jewish ancestry. Hitler granted him the title of "honorary Aryan."
Such claims have also been made of Tomas de Torquemada, who was descended from converted Jews on his mother's side. It's actually a common saying in Spain that "there's no worse fanatic than a convert".
Leo Felton who planned to blow up Black memorials in America is the son of an African American father. He came up with convoluted theories to argue that he was white rather than black, most notably arguing that race was more spiritual than biological. He later evolved into an all-out Boomerang Bigot.
It's very likely that Charles Manson, whose many flaws included strong racial bigotry and whose grandiose schemes included provoking a race war that would ultimately leave him in charge of the presumed black survivors, was part black. Not obviously so, but just the mere fact...
Dan Burros was a Jewish member of the American Nazi Party. Though his colleagues knew he was Jewish, his heritage was hidden from the general public.
Often time, somebody with racist beliefs will find out that they have an ancestor of that race. This may or may not change their beliefs.
In 1999, a gang of Swedish neo-Nazis became infamous when they murdered two police officers. One of the gang-members, Jackie Arklöv, was biracial.
All Child Haters used to be children once.note Some may still be children. Of course the greatest fear of young people who express contempt of "old farts" and "wrinklies" is that they will look like that themselves one day.
Certain fandoms tend to receive flak, such as Furry Fandom, yet a sizable number of people who tend to criticize certain fandoms are, to some extent, part of them.
An interesting example would be bigotry amongst different Abrahamic religions, particularly Christianity, Judaism, and Islam. Antisemitism was widespread amongst Christians just a century ago, and some religious groups still hold to such beliefs nowadays. Many Muslims , too, don't like the Jews too much, what with the Arab-Israeli conflict and everything. All of them, however, tend to forget that all good guys in the Old Testament (which is the basis for both the Bible and Qur'an) are Jews. Christ was a Jew, too. Though Christian and Muslim anti-Semites often make up various theories as to why the Israelites of the Old Testament are different from the Jews of today, these theories generally don't hold water.
Also, some Christians and Jews who disapprove of Islam, especially the more draconian aspects of Sharia law like killing apostates and mutilating thieves. These laws have their origins in the Old Testament. The reason why said laws are rejected is that most people feel that they were established at the time for a people, rather than forever (or rationalize it as a misunderstanding of what God "really" meant). The Christians, at least, have a canonical reason for it; Jesus was very benevolent and forgiving, and encouraged his followers to follow in his footsteps.
Chris Rock: One of his most famous bits is explicitly about this; he says black people are more racist than white people because black people hate black people too before moving on to a discussion of N-Word Privileges. He has said in one of his routines that this is why it doesn't make sense to hate people:
It don't make no sense, because whoever you hate gon' end up in your family. That's right, you don't like gays, you're gon' have a gay son. You don't like Puerto Ricans, your daughters gonna come home livin' la vida loca.
This story about a half-German, half-Chinese kid who refuses to identify himself as Chinese.
Hermann Göring's younger brother Albert was said to be a product of their mother's affair with a Jewish friend of the family. Partially subverted in that Hermann loved Albert and kept him from being arrested, even though Albert was a member of the German Resistance who openly and frequently protested the treatment of Jews by the Nazis and who later on passed state secrets to the Czech Resistance.
A lot of Closet Geeks are this. They are at the very least ashamed of their geeky interests and will hide them from others in an attempt to appear more normal (aka "hiding your power level"). They often fall into Armored Closet territory where they will publicly bash geeks and geeky things. Most don't really mean it and only do it to take suspicion off of themselves, but some are genuinely self-loathing and wish that they were normal and didn't enjoy these uncool geeky things so much.