Yglesias looks at Brown's record and wonders what sort of Senator he will be:
The evidence from state of the art political science is that Brown’s voting record as a state legislator is actually incredibly liberal for a Republican. But his campaign didn’t really emphasize that fact, and his statements on forward-looking issues (no on health care, no on cap and trade, yes on tax cuts) don’t indicate any particular desire to break with conservative orthodoxy. And yet, I think the baseline view that Massachusetts is a liberal state that’s not going to re-elect an orthodox conservative still seems pretty compelling.
Ezra Klein argued yesterday that party loyalty trumps everything.