Picked up this interesting article off of Google News. It's an editorial from the heartland, and it sums up much of the discontent Bush is feeling from his own party. He's running into trouble because of the same factor that got him elected:
"The Base" doesn't like politicians.
In particular, they don't like slick-talking big-city shysters that twist words around, say one thing, and do another. Bush's appeal was that he was a straight-talking down-home country boy -- a man of the people. Now he's been outed doing the one thing that, according to the base, set him apart from his predecessor: using his office for personal gain.
(Related article from the Christian Science Monitor)