Obama did well with swing voters in 2008 and can do so again. The key is to keep reminding his supporters that he was elected to fix Washington, not put up with it. By definition, independent voters don't care about party labels and disdain partisan gamesmanship. They want Obama to keep pressing both parties to work together—no easy trick these days—and they want their president to be a spur to congressional action and a check on congressional excesses.
Third, health care retains its title as the Middle East of domestic policy. Democrats should find a way to get some form of health reform done, because, as Bill Clinton has reminded them, we know what happens to Congress when it fails to act. But on no issue is the gulf so great and so persistent between the need for national action and people's trust in government and the political system to get the job done right. Scott Brown is living proof of health care's exasperating contradictions—a man elected to the Senate for opposing for the country what he voted for in Massachusetts.
Finally, Democrats should remember that a party willing to take voters' lessons to heart has the chance to build a strong, more enduring bond with the electorate because of it. In 1994, Bill Clinton took the voters' message as a directive to govern the way he campaigned and be the president he was elected to be, not the president Congress wanted him to be.
The country didn't change teams on Tuesday. Americans still want Obama to succeed and still trust him to run the country far more than the other guys. As Curt Schilling might say, the Massachusetts race was more of a brushback pitch—a warning to those in power without regard to party that an electorate in a foul mood is always a force to be reckoned with.
The best advice for Democrats might come from Kevin Millar, another member with Schilling of the famed squad that went on to reverse the Red Sox curse. Millar made the team motto "Cowboy Up"—which means get back up, dust yourself off, and make sure it doesn't happen again. In politics, like baseball, what matters in the end is not what happened last game, but who's standing tall in November.