Yeah, I can take a stab at it.
Before the election cycle rolled in, I never got the impression that Scott Brown was against health care. Even now, we see him backing off that sorta-famous quote from the debate "I will be the 41st vote. I will stop [health care]." I think the country needs to understand that the bill SB and others voted for in MA is basically the grandfather of the bill that went to the Senate floor. The only difference between the two (again in my opinion) are the political winds.
In MA, Scott Brown supported the health care because it was a more bipartisan effort and it was driven, in large part, by a Republican governor. Romney really pushed it (I believe for political gain), comparing it to car insurance and saying that we force everyone to have cars and people are a lot more expensive than cars.
When Scott Brown declared for this election, he was a 30 point underdog. Coakley really let Brown define himself any way he wanted to and I believe he saw people's uncertainty over the bill and capitalized. It was one part of his "I won't be a rubber stamp or a pawn in the system" message that resonated with voters.
Please don't take this as me saying Brown is nothing more than an opportunist or anything. I'm actually fairly happy that the bill is at least being reconsidered right now. I do believe, though, that Brown's waffling support on health care has much more to do with the political climate than any higher belief in constitutional rights or anything like that. My girlfriend works down the hall from Brown's old office and neither she nor I have ever gotten the message from any of his actions or statements that he's a strict adherent to the principles of the constitution.