BEWARE OF SPOILERS. Due to the nature of the show, with its many Walking Spoiler characters, twists, and turns, the only spoilers whited out are those for the current season "24: Live Another Day". Proceed with caution!
White House Chiefs of Staff
The Chief of Staff for David Palmer in seasons 1-2 and later for Charles Logan.
- Et Tu, Brute?: His betrayal of David Palmer.
- Honest Advisor: Except during Day 2, unfortunately.
- Honor Before Reason: Starts becoming this in season 4. Before that he is a hardcore pragmatist.
- Karma Houdini: Despite his role in inadvertently causing the possible death of Lynne Kresge, he's never charged or imprisoned for it, and goes on to work as an adviser for another presidential administration.
- Manly Tears: He has some when he finds out David Palmer was assassinated.
- My God, What Have I Done?: His attitude by the end of Day 2. He ultimately winds up coming through by the end, but it's not enough for Palmer to forgive him.
- Put on a Bus: At the end of Day 2, he's fired by David Palmer.
- The Bus Came Back: On Day 4 he returned as Logan's adviser.
- Screw the Rules, I'm Doing What's Right!: Informing David Palmer about Walt Cummings' plan to have Jack assassinated when he would be turned in to the Chinese... and of course working with Jack to expose Logan.
- Single Tear: At the end of Day 2, when President Palmer has fired him and he realizes that his actions have ruined their friendship.
- We Used to Be Friends: With David Palmer (though they are at least later able to patch things up, especially when cooperating to help Jack escape)
- Well-Intentioned Extremist: During Day 2.
The White House Chief-Of-Staff under Charles Logan during Day 4 and 5.
- Alas, Poor Villain: Make no mistake: Cummings is a gigantic Jerkass, incredibly smug, and a traitor to his country, but the way he goes out is so pathetic that one can almost pity him.
- Big Bad Wannabe: While he did have some involvement in the Sentox conspiracy, he mistakenly believes he's one of the masterminds behind it. His true role was to keep anyone from discovering that Logan was also involved.
- Character Death: Cummings seemingly hangs himself after his plans were exposed, but Henderson implies that his death was ordered.
- The Dragon: To Logan.
- He Knows Too Much: The likely reason for his death.
- Never Suicide: Henderson strongly implies that Cummings' death was ordered by Logan.
- Nice Job Fixing It, Villain!: If Cummings had decided not to orchestrate the assassination attempt on Jack's life and had just let him willingly be taken in by the Chinese at the end of Day 4, then very likely when the events of Day 5 happened Jack would have still been imprisoned in China which would have left him unable to expose its conspiracy.
- Smug Snake: Like the Unwitting Pawn trope states, he believed he was much more of a major player than he actually was, which allowed his eventual downfall to hit him that much more harder before he's betrayed by the very folks he thought were working for him and killed.
- Unwitting Pawn: He thought he was a major member of the Day 5 conspiracy. He was actually the lowest member, and was just there to be a scapegoat.
- Well-Intentioned Extremist: Check his quote.
White House Chief of Staff under Presidents Wayne Palmer and Noah Daniels.
- Brutal Honesty: Tom speaks his mind, whether people want to hear it or not.
- Deadpan Snarker: He has a very vitriolic and bitter sense of humor that comes through frequently.
- Everyone Has Standards: Tom might be a jerk, but he has morals."Nothing justifies the killing of a president."
- Fake Defector: He pretended to go along with Reed Pollack's assassination attempt on Wayne Palmer so he could expose his treachery. Although he failed to get word out before the attempt was made, he still immediately confessed to what happened when it appeared Pollack had succeeded in buying him off.
- Good Angel, Bad Angel: The Bad to Karen Hayes' Good.
- Honest Advisor: To everyone. Tom doesn't sugarcoat things, and will tell the hard truth.
- Jerk with a Heart of Gold: Tom is introduced demanding to revoke the rights of U.S. citizens, and otherwise he's sarcastic, snippy and irritable. However, despite his disagreements with Wayne, Reed Pollack's attempts to have him assassinated disgusted Lennox and he did his best to expose the plan. He also convinces Noah Daniels to pardon Karen Hayes for her going against protocol to warn Jack, and the two part ways on friendlier terms despite their earlier hostility toward each other.
- Morality Pet: Amazingly enough manages to be this for Daniels.
- My Country, Right or Wrong: Everything Lennox does is to protect his country. Noah Daniels learned the hard way that Lennox will stand up to anyone who tries to harm the U.S., even if it's the Vice President."Well sir, I'm on the side of the United States of America, and if you ever thought otherwise, you're very much mistaken."
- The Rival: To Karen Hayes.
- Villainous Breakdown:"I have no influence!"
- Well-Intentioned Extremist: Tom wants to set up detention facilities for U.S. citizens who have committed no crime in the interests of protecting the country.
Defense Secretary under Wayne Palmer and Noah Daniels, before becoming Chief of Staff and later Secretary of State under Allison Taylor.
- Ascended Extra: Goes from being a relatively minor player during Day 6 to one of the central characters in Days 7 and 8.
- Honest Advisor: To Allison Taylor.
- Hypercompetent Sidekick: Just look at his resume. Kanin's served as Secretary of Defense, Secretary of State, White House chief of staff, and is implied to have run Taylor's presidential campaign.
- Morality Pet: For Allison Taylor, particularly when she goes down a bad path.
- Nice Job Breaking It, Hero!: It was his idea in the first place to call Charles Logan in during Day 8. Of course, he also admitted then and there it wasn't the best idea.
- Properly Paranoid: In both Days 7 and 8. He worried about welcoming Olivia Taylor back into the President's administration given her ruthlessness on the campaign trail. Sure enough, her impatience with her mother's decision to pardon Jonas Hodges leads Olivia to ordering a hit on the man. In the final few episodes, he brings up the possibility of turning using Charles Logan as an ally, but quickly comes to regret the idea when Logan arrives, as he becomes worried that the former president could corrupt Taylor's administration. Once again, Taylor starts to betray her principles due to Logan's influence, and Kanin, disappointed, resigns to avoid watching his friend descend further into Logan's grip.
- Screw This, I'm Outta Here!: Quits as Taylor's Secretary of State after it becomes clear that she's fallen completely under Logan's spell.
- Suspiciously Similar Substitute: Less so in Day 6, where he's just another of Palmer's and later Daniels' advisers, but in Days 7 and 8 he takes on pretty much the same role that James Heller did in Days 4 and 5.
The daughter of Allison and Henry Taylor and First Daughter of the President.
- Bodyguard Betrayal: An unusual case, especially when compared what happened to her father. While Henry Taylor was trying to uncover the truth behind his son's death and was betrayed by his guard to cover up the conspiracy, Olivia was herself trying to cover up her role in Hodges' death, and was betrayed by Aaron Pierce when the latter helped Ethan Kanin in exposing the truth.
- HeelFace Door-Slam: Tries to call off the hit on Jonas Hodges, but is too late.
- Out-Gambitted: Manages to outwit a reporter who tries to blackmail her by recording their affair and threatening to go public with it. It happens to her as well. She destroys the tape Ethan Kanin was carrying, thinking that it held the evidence of her complicity in Jonas Hodges' murder. However, it turns out that Kanin gave the real tape to Aaron Pierce instead (something Olivia would never expect, given how loyal Pierce had been to her up to that time), and she is subsequently forced to face prison time when her mother discovers what happened.
- Revenge Before Reason: She arranges the death of Jonas Hodges despite the huge negative impact it would have on her mother's presidency, her own life and the pursuit of his co-conspirators.
- Suspiciously Similar Substitute: Much like how her mother represented being the new Big Good ala David Palmer, Olivia seems remarkably similar to Sherry.
- Tears of Remorse: Breaks down crying at two points in the season. First, when she thinks she will die in Juma's attack (as she regrets living a life estranged from her mother) and second when forced to confess her role in Hodges' murder to her parents.
The second White House Chief of Staff for the Taylor Administration after Ethan Kanin became the Secretary of State.
- Even Evil Has Standards: Although he was willing to go along with Bruckner's plan, even he had to admit letting Ethan potentially die from a heart attack just to keep him from alerting President Taylor was a bit extreme.
- I Did What I Had to Do: His basic excuse for conspiring with Bruckner.
- Jerkass: He wanted Renee Walker to take the fall for the failure of the Vladmir Laitanan mission, and had the gall to get angry about it when Bob Hastings refused to do so.
The Chief of Staff and son-in-law of President James Heller.
- The Atoner: Mark becomes this after the disaster with Stolnavich and his subsequent My God, What Have I Done?.
- Blackmail: From the Russians when Stolnavich discovers he forged the president's signature.
- Break the Haughty: He is near catatonic in his last scene, with Audrey dead and Mark himself awaiting his transfer to prison.
- Cowardly Lion: Admittedly his cowardice is a key ingredient in his downfall, but he does demonstrate some balls of steel by infiltrating the Russian embassy, and then when things go south, immediately disarming Stolnavich and killing him in the brawl that follows.
- Despair Event Horizon: Following Audrey's death.
- Disaster Dominoes: One little decision — forging Heller's signature — and the increasing need to cover it up spirals into catastrophic consequences, namely a narrowly averted war with China.
- HeelFace Revolving Door: For a while until his jealousy pushed him over the edge Mark seemed to show increasing reluctance with his decision to falsify the executive order. And when the time comes, he helps carry out his father-in-law's final orders rather than sabotage them. After discovering that Stolnavich was working with Cheng Zhi and is brought up on treason charges as a result, he makes yet another turn and agrees to help Jack take down Stolnavich in an attempt to set things right.
- Inspector Javert: He pretty much assumes the worst of Jack from the beginning and wants him taken out of the picture in any way.
- Jerk with a Heart of Gold: Mark can be jealous and irritable, not to mention he makes some truly awful decisions. However, he does try and do the right thing. He loves Audrey and helped her recover from a terrible ordeal, he has a genuine love for his father-in-law and tries his very best to help him. He even manages to put his jealousy aside to work with Jack when it really counts. When he does betray Jack to the Russians, he's consumed with guilt and puts his life on the line to make amends.
- My God, What Have I Done?: Upon realizing that giving away Jack's position to the Russians caused the loss of the override device. It gets worse upon discovering that Stolnavich is working with Cheng Zhi.
- Nice Job Breaking It, Hero!: He gives up Jack's location to the Russians to avoid getting in further trouble with them - right as Jack and Kate are in the middle of trying to recover the override device.
- Secret Keeper: He and Audrey are the only ones who know Heller is beginning to suffer from Alzheimer's Disease.
- Slimeball: As the season goes on, it becomes clearer that Mark's attempt to get rid of Jack is moreso out of jealousy than anything else, and the lengths he goes to so he can keep everyone else from discovering he forged executive orders all so he can save his own hide culminate in him selling Jack out to Russia while Jack is in the middle of trying to prevent a war from being instigated.
- Tragic Mistake: One of the most crystal-clear examples of this trope the show has ever offered. Mark's initial motivation is to protect Audrey both physically and emotionally; the unethical action he takes in order to achieve this directly leads to her re-traumatization at the hands of her former torturer Cheng Zhi, and then her eventual death.
Other White House Employees
A crisis-management advisor for David Palmer.
- Hyper-Competent Sidekick: For David Palmer. Lynne is deeply loyal and extremely competent.
- Undying Loyalty: To David Palmer. She refuses to go along with Mike's plan to oust him.
- "The Reason You Suck" Speech: Gives one to Sherry.
- Screw the Rules, I'm Doing What's Right!
- What Happened to the Mouse?: Last seen in critical condition being wheeled into an ambulance, she never reappears after Season 2. Given how Mike Novick, who inadvertently put her in that situation, continues to serve in a high position of the Keeler and Logan administration's, this would likely mean Lynne either died or survived and refrained from speaking out against him.
A high-ranking member of James Heller's administration and a colleague of Mark Boudreau, who accompanied the First Family and General Coburn on their trip to London, England.
The Deputy Chief of Staff at the White House during the events of Day 6. He served under Tom Lennox, who was President Wayne Palmer's Chief of Staff.
Pollock was willing to bend the rules in order to get things accomplished. Under the instruction of Lennox, Pollock was responsible for Karen Hayes' resignation during the early hours of Day 6. However, Tom soon realized the lengths Reed went to in order to achieve his goals, were considered treason. Reed was arrested by Secret Service, along with Bruce Carson, after he was implicated in the assassination attempt on Palmer.
- The Conspiracy: Reed is part of a conspiracy to remove Wayne Palmer from office.
- Even Evil Has Standards: He really doesn't want to kill Tom Lennox, and stops his co-conspirator Bruce Carson from doing the same.
- Horrible Judge of Character: Kept believing Tom Lennox will help with the plot.
- Smug Snake: The second he thinks he's finally gotten Tom Lennox under his thumb, Lennox almost instantly proves him wrong by immediately confessing what he did to the nearest Secret Service agent.
- Well-Intentioned Extremist: His intentions are genuine, but his methods are treasonous.