In his pan of the boring Brüno, Houston Chronicle Film Writer Mick LaSalle makes the point I've been waiting for:

In one scene, Brüno gets former presidential candidate Ron Paul, R-Lake Jackson, in a hotel room and tries to seduce him. Paul rushes out of the room horrified and, guess what, it’s not funny: A serious, accomplished man takes time out to do an interview. He’s treated appallingly, reacts with anger … and we’re supposed to think less of him? Don’t think so.