Rush often gives simplistic explanations for things. Supposedly the media and the air in Washington corrupts these people. No, they are scared by some of the polls, and by the independent, moderate, or even liberal vote in their states, which they think they need. Sad fact is the country is not the big red bouldozer the conservative commentators paint it as. There are plenty of damn moderates/ liberals in them there hills.
I agree with Sure_fine, term limits would go along way to preventing the problem.