Anybody but the extreme right wing has to admit that the 'left' has gotten virtually nothing from the Obama Administration since he took office. Denied on Afghanistan, denied on health care reform, denied on the Patriot Act, surveillance and detentions, denied on DADT.....and the Administration is just about as centrist as you could create. I think a good many of the 'Independents' in Massachusetts are disgruntled Democrats, either fed up, or pursuing a strategy of sending a message to the White House.
The scaremongering of a mythical 'far left' menace by the right was masterfully played...but demonstrably false. But even though the 'far left' myth continues.........Obama is a tried and true centrist. He has continued nearly all of Bush's policies. Democrats are supremely disappointed in him...and Republicans hate him. He's squarely in the middle.
Amid the rhetoric, most Americans can't even define actual Socialism, much less know what one looks like. What we've seen lately from the opposite party however, is Republicans attempting to re-brand themselves as Libertarians, as opposed to the other way around.
The pendulum swings but only in a short, centrist arc. I do however believe, that like Massachusetts electing a Republican Senator for the first time in a few decades....we're likely to see a Democrat take an equal district in a southern state that has been red for quite some time.
So while the right spins the Brown victory as a harbinger of good times ahead, the response from the left will be swifter in further marginalizing Republicans. The Democrats will get pass some legislation while taking credit for getting it done in spite of Republican obstruction. The victory in Massachusetts could end up costing the Republicans more seats in the long run.