It doesn't happen very often. At least it didn't used to. Until recently, the Republicans have held a very strict discipline. They may have their disagreements in private. But in public, they never speak ill of another Republican. They always vote as a block. And they always have the same talking points. So what's to make of the recent refusal of over 80 Republican Congressmen to vote against the 2011 budget compromise? It seems like an escalation of a simmering tension between the Tea Party and the GOP center.