Sarah Binder at The Monkey Cage has a post on Senator Hatch who faces a primary challenge next year from a tea party candidate. In my memory he was a right wing conservative. I identified him as such when he was first elected to the Senate, and he was. He was much to the right of the center of gravity of the Republicans in the Senate. Now it seems he is much to the left of the center of gravity, not because he's changed particularly, but because the Republicans have moved rightwards. More accurately, as old Republicans have been defeated or retired, the new Republicans who have been elected are much more conservative.