I'm not understanding why folks think Brown betrayed them. It was clear all along that Brown was a moderate pubbie - but in MA, that was a major improvement over the Dem (and it was a harbinger of November 2010 that the GOP was able to take Ted the Swimmer's old seat). So in Brown's election, the establishment was gunning to win a new seat, not protecting an incumbent RINO from a Tea Party challenge.
I'm all in favor of trying to primary Brown and the Maine twins the next time around. But it's absurd to pretend that Brown sold himself as something that he is not now.
I found your post astute to that point. I don't think we can do better in Mass than Brown. We would be trading a Rockefeller Repub for a hard leftie.
Can we do better in Maine? I'm inclined to risk it...as a matter of principle. We can't let RINOs get too comfortable, and the Girls have been there long enough.