Obviously - the best possible candidate Massachusetts Republicans have in this district. But even that may be not enough. Especially - in Presidential year. I have little doubts that he could win in 2010, but that time Republican candidate was an idiot Hudak. In 2012 it will be more difficult..
Well if Romney is the nominee he will at least have an excellent chance of getting over 40% of the vote, so that might be enough to prevent any Obama coattails. He seems liberal enough to win the district in a presidential year.