Continuity mistake: When they are arguing in his bedroom, her scarf and coat are closed at one point, then open, then closed.
Continuity mistake: When the President comes home, right before Sydney tells him that he lost her vote, he is walking up the stairs and unbuttoning his jacket. However, in the next shot, he goes to kiss his daughter, and his jacket is buttoned again.
Continuity mistake: In the first scene where President Andrew Shepherd encounters his daughter practising the trombone in her room, he talks to her about a parent-teacher conference and hands her a book. In the shot where he hands her the book, it is right side up for the girl to open easily. In the shot where she receives the book, she has to turn it around to open it. (00:10:45)
Continuity mistake: When the two aides are discussing the President, the aide with the beard plops Alka-Seltzer in a glass. It fizzes and then the next shot he's drinking plain water again.
Continuity mistake: In the meeting room with the White House Chief of Staff, Sydney is giving a self-righteous speech about the President being president of Fantasyland. When the President walks into view, she immediately stands up from her chair. Then in the next shot, she immediately stands up again. (00:16:55)
Continuity mistake: The morning after the President and Sydney have spent the night together for the first time, while Sydney is getting dressed to leave, the collar of her turtleneck sits flat in the front (around her neck), but in the next shot the same collar is dog-eared in front, then goes back to sitting flat. (01:06:40)