Otto Preminger directed this to show how evil the Senate is. The president has nominated a new Secretary of State so he's (Henry Ford) being interrogated in committee. Committee has let a non-committee person, the senior senator from South Carolina (Charles Laughton), sit in and interrogate, too. We see that Laughton has put in someone as a witness (Burgess Meredith, who in real life was named by HUAAC) who is lying, except for one thing. Ford goes to the president to tell him that when he was in college, he was in a Communist cell for a short time. The president keeps him in nomination.
Then Laughton found something bad about the committee chairman (Don Murray, playing a Utah senator with first name Brigham) and has someone calling his wife and scaring her before there's info on someone she doesn't know. Murray dashes to New York where he gets more specific info and when he gets there, it's a gay bar. The guy he was with in Hawaii is there and is trying to catch up with him.
Murray comes back to his office and kills himself in the bathroom. The committee takes the nomination to the Senate but Laughton has managed to change some votes that were expected and the vote is even. The president dies (why he wanted Ford as State -- he needed someone who knew what they were doing when he was dead) and the vice president decides not to vote, which means the nomination is dead.
Deciding not to vote is an interesting choice because it's not evident whether Preminger thought the vice president was automatically moved up to president (has to be sworn in, he could have still voted) or if he meant the vice president to strike out on his own ideas. He hadn't had his own ideas before.
This was a really good movie, as far as the plot and the actors. The pretend pictures of DC weren't so good.