If you are a die hard conservative like myself, Scott Brown was a heartache. I even volunteered to make calls on his behalf during his race to become the Senator from Massachusetts to take "Ted Kennedy's seat". He promised to be the vote for the filibuster of Obamacare. Of course once he pulled off that remarkable upset victory, the Democrats ran an end-around and his win did nothing to prevent
Hillarycare Pelosicare Obamacare from becoming law.
And since then, Scott Brown has taken a number of decidedly unconservative positions that have disappointed conservatives across the nation who had previously cheered him on. The seat was going to be up for re-election in 2012 and Scott Brown has got to run again after only a couple of years in the seat. He's up against a long time supposedly neutral but very liberal Democrat next year. It's probably an uphill battle for him and one many conservatives don't mind if he loses.
According to the Washington Post, Scott Brown voted with the majority of Republicans 80% of the time. In the same poll, "56% of Massachusetts voters believed he has kept his promise to be an independent voice in the U.S. Senate."
Despite liberal positions on many things, he did vow to work against Obamacare. In 2013, after president Obama loses his re-election bid, every vote in the Congress and Senate is going to count in the effort to repeal this monstrosity - even a RINO vote like that of Brown.
In his defense you could argue that he has to be liberal on some stuff in order to secure the votes he needs to win. Massachusetts is a really blue state. But you don't even need to make that case. If all he helps Republicans do is repeal Obamacare, all that effort, all his other liberal foolishness will be a small price to pay to repeal trillions in unfunded benefits. At least that's what I keep telling myself to help deal with the volunteer work I did for him in 2010.