To interpret this as any kind of swing to the right in voter sentiment, though it will be in the popular media, is not a tenable argument to any serious student of politics. Voters who have checked out of the Democratic party after a year of no change save the continuance and expansion of Bush-era policies, like warrantless wiretapping, extraordinary rendition, failure to prosecute torture, bailouts, including a new one for insurance companies, and most of all, more war, make this election most comparable to what happened to Bush Senior in 1992 after he broke his no-new-taxes pledge to his base. They stayed home, allowing Clinton to skate to victory. Betraying the base is always a hazardous occupation.
Obama promised "two or three more battalions" in Afghanistan, a miserly 10,000 more troops. He did not campaign on a tripling of the 30,000 he found there, and a ten to fifteen year campaign, as McChrystal has said, immediately backpedaling on Obama's already nearly meaningless withdrawal suggestion of 2011 "subject to conditions on the ground." Iraq withdrawal has turned into a 50,000 troop "residual force" outside of any timeline, translation: permanent bases.
As Mike Capuano, distanced from Obama's continuation of Bush-ear policies by his strong stand against the Patriot Act, might have overcome the negatives with his somewhat cultivated "maverick" image combined with his trademark dose of good old-fashioned street-fighter against Brown. Coakley, with her thoroughly unattractive baggage as a prosecutor who kept an innocent man in jail to bolster her "law and order" credentials, her defense of the Patriot Act, and her general lack of distinction as anything other than the Democrat in the race, made it just too hard for too much of the state's progressive base to pull the lever.
The only thing clear now is that Charlie Brown ain't running at Rahm Emanuel's football no more, the penultimate insider and guru for the Democratic party's political playbook. A strategy which talks left but acts right, and takes the progressives' votes for granted, because after all, there's a boogie man out there. Rahm and the Democratic establishment which took a voter-granted majority in 2006 to end the Iraq War and then went along with Bush's surge, which mouthed the "no one is above the law" in the playbook and then allowed Bush-Cheney to be above the law, put out that football one too many times, and this time Charlie declined.
Rahm, meet US Senator Scott Brown.