Factual error: Towards the end of the movie when the President is addressing Congress, Joan Allen is seen outside of the building jogging. Joan Allen, being a senator and thereore a part of Congress, should have been inside the building.
Continuity mistake: In the beginning of the movie there is a scene where Joan Allen is walking next to the President. If you look closely at her feet, she is wearing two different colored high heels.
Continuity mistake: At one point when Runyon and his advisors are plotting how to undermine Hanson, the cigar he is smoking alternates length dramtically between shots.
Factual error: At the end of the film, President Evans addresses a joint session of Congress, which is always held in the chamber of the House of Representatives. The room used in the film looks nothing like the real chamber: it has windows (the House and Senate meet in windowless chambers), is panelled in white (the House and Senate chambers are panelled in dark wood), and is not large enough to seat the 435 members of Congress, let alone the 100 senators who may or may not be in attendance. We know from State of the Union addresses that the House chamber can hold all 535 members of Congress, the Supreme Court, and the Cabinet with room to spare.