Here's Alan Keyes, I know hardly mainstream, but still - he was the Republican pick for US Senator in Illinois running against Obama, and he run for president in 2008 (I bet you didn't know it).
But I've heard folks like Rush Limbaugh be similarly shrill.
I know, I know, there were folks on the left saying similar things about G. W. Bush, but at least most of that came after Bush showed some solid years of ineptness. How long has Obama been president? 1 month? This mess is still Bush's not Obama's, lets not forget it.
Anyway, watch for yourself: