Populist
He can be as irritating to the right as he is to the left.
You may or may not know that he has been critical of the Bush admin for the lack of WMD in Iraq. He was for the Iraq reconstruction money being loans instead of grants. He also is against CP and is for the decrim of marijuana. I think he claims to be pro-choice but he is catholic and I might be wrong.
I would liken him to a sports columnist that lives on controversy. He will criticize anyone or any team for the attention it gets him and he is always perceived as a homer for your rival.