What do looks have to do with anything? It's quite an unintelligent argument. She'd probably rather stay in the House than get caught up in a primary that has candidates already interested.
Because she is ugly, and she is a bitch. Thats why. And my previous argument is valid sir, because I own a horse. Also, as cinyc said, and I have said earlier, why get into a primary that she may just barely win, and give up her senority in the House to be a Senator with nothing. Plus, she is old, its not like she is Murphy, who has the time to build something up.