Common reasons for a Race LiftGenerally, a Race Lift works in one of these ways:
Analysis: Ability over AppearanceThe most common justification for a Race Lift is that a part should go to the best actor for the role, regardless of the character's original race or appearance. This raises several questions.
The Importance of "Bankability."Another common justification for changing a non-white character to a white one is the supposed importance of having a "bankable" actor. A big-name actor is needed to bring in crowds and most big-name actors happen to be white. However, that raises the question of why most big-name actors are white and whether actors of different races are being given the same opportunities to become big-name actors. In the words of George Takei, "How would you get someone who has a track record, if they donít give anybody the opportunity to run on that track?" One could also question the importance bankability itself. For example, Daniel Radcliffe and Robert Pattinson were not particularly well known when they were first given their lead roles in Harry Potter and Twilight, respectively. While bankable actors can cause hit movies, it seems that the reverse is true as well. So the question is whether studios are more willing to take the "risk" of an unknown lead actor if the actor is white. Finally, there are a few examples of a lead white character being played by a famous non-white actor. For example, Will Smith played Robert Neville, the lead in I Am Legend.
Minority-to-White vs. White-to-Minority Race Lifting: A Double Standard?Many of those who oppose changing a non-white character to a white one are less opposed, or even supportive, towards a white character being changed into a non-white character. Some claim that this is a Double Standard. The most common response is that changing a white character into a non-white one is more acceptable due to the lack of roles, especially lead roles, being given to non-white actors. For example, even after changing the race of Nick Fury in The Avengers, literally every other superhero and almost every single speaking character in the film was still white. Whereas not only are there few counter-examples in any type of media with majority casts of non-white characters out there, but race-lifting these characters in adaptations is a lot more damaging, taking away even more of what little representation these characters' racial or ethnic groups have, as in The Last Airbender.
How do we determine someone's race?This is more complicated than it might seem at first glance. A person's race can be determined a number of ways, including ancestry, appearance, and self-identification. For example, The Lone Ranger was criticized for casting Johnny Depp as Tonto, a Native American. However, Depp does claim to be one-sixteenth Cherokee and the Cherokee tribe has no minimum "blood quantum" requirement to be a member so long as one can claim matrilinear descent from a Cherokee woman. Furthermore, Depp was adopted by the Comanche tribe, which is a perfectly legitimate way of making him a member of the tribe. Another example is Tony Mendez, the real-life CIA agent who was fictionalized in Argo. The film was criticized for having the white Ben Affleck play Mendez, who is half-Hispanic and appears Ambiguously Brown. However, Mendez is half-white and self-identifies as white.
History of Race LiftingBefore about 1970, it was common for TV stations in the American South to edit shows featuring non-stereotypical black characters to remove their scenes. In cases where the character couldn't be edited out, the episode or the entire show wouldn't be aired. Producers therefore had an incentive to choose an all-white cast even if the original characters were intended to be minorities. (One of the first shows to attempt to break this barrier was Hogan's Heroes, which made Kinchloe the second-in-command and the camp genius so he couldn't be edited out.)
The effect of Race Lifting on multiracial and racially ambiguous people.Simply because of the need for visual diversity, some actors and actresses get the short end of the deal. People of mixed race are especially prone to this because they don't look enough like one ethnicity or the other. See Half-Breed Discrimination. And sometimes people are entirely one ethnicity but have the "appearance" of another. There are White Hispanics with visibly-fair features (Cameron Diaz, for one; Spaniards as a whole), but that is not what the general American viewer sees as a stereotypical Hispanic (at least according to Hollywood and other mainstream media). There are some black people who appear to be white. There are even some Filipinos and Samoans that appear to be black. Occasionally this process will only be carried out halfway, with a previously ostensibly white character being retooled as someone with a secretly mixed background. In the United States, it has often been common for an especially daring or renegade character to turn out to have American Indian ancestry, if only to emphasize their "wildness". This is plausible because racial mixing with Indians, while not uncommon, was never as widespread or ubiquitous in the U.S. as it was in Mexico or even Canada, partly because there were far fewer Indian people for breeding material; the result is that many white and black Americans have bloodlines that are so diluted that they can claim to have Indian ancestry without actually looking the part.
Race Lifting in sci-fi and fantasy.There's also a (much less common) version specifically for scifi adaptations of historical works, where Africans/Asians/Arabs who were intended to be exotic in the original are changed to something that actually would be exotic for humans in the far future. The usual choice is some odd kind of alien while the humans usually end up being represented by white people. In Fantasy stories based on Literature, Comic Books or Manga, many times the name of the ethnicity never comes up because it wouldn't exist in that world. When that happens there can be serious arguments and flame wars over what ethnicity a certain character is, based off of the Fantasy Counterpart Culture that might have been used. Their physical appearance might not have any particularly telling markers and clothing can just be added flavor. So if there is an adaption of that work and fans have their own expectations of a particular ethnicity you can guarantee a flame war.