2012 Primaries

The 2000 and 2006 Senate elections both went well for Democrats, which means they have a lot of ground to defend in 2012 and will probably lose seats. But there's also the chance of a number of GOP incumbents facing primary challengers, including the very popular Scott Brown:

"I think that there will be a primary challenge," said Christen Varley, president of the Greater Boston Tea Party. "There's enough of an underground movement in the Tea Party movement as seeing him as not being conservative enough. There probably will be multiple people who attempt to run against him."

To the best of my knowledge, moderate Republicanism remains a pretty strong force in Massachusetts where beyond Scott Brown a series of moderate Republican gubernatorial candidates ran and won statewide in 1994, 1998, and 2002. But you would have said the same about Delaware until 2010, so anything's possible.