This story is from California, but I imagine it's being repeated in pretty much every state in the union:
Until recently, many Democratic strategists believed that incumbent Sen. Barbara Boxer was a prohibitive favorite for reelection in November and that their party's presumed candidate for governor, Atty. Gen. Jerry Brown, would coast to victory. Now, confidence has faded on both.
....Boxer sought to reassure supporters that she knew she had a battle ahead. "Every state is now in play, absolutely," she told reporters in Washington. The lesson from Massachusetts, she said, is "never, ever, ever take an election for granted."
I don't want to pretend that there's a silver lining for Democrats in Martha Coakley's defeat on Tuesday. There isn't. But if there were, this would be it. At least nobody's going to be coasting from this point forward.