Brewster also wasn't the only Senator that Hughes had a beef with, either. The scene in Tucker: The Man and His Dream where Tucker met with Hughes is based on Tucker's account of his meeting with Howard Hughes. Supposedly, Senator Ferguson, who spearheaded the Feds investigation against Tucker, was more corrupt than he was portrayed in the film. (No idea how accurate that info is, so take it with a grain of salt.)
The History Channel was showing clips of Hughes, in promos for a show on him (missed it, so I can't say what was in the show) where he lashes out at Congress, so it's certainly possible that the film's accurate in that respect.
***Don't ask me, I don't post here any more, and I'm probably not even reading this now.***