Yeah, OK, so I'm a bit weird in what switches me on.
The New York Times' chief polling analyst just wrote, "If our forecasts turn out to be biased against Democrats by just 2 points overall, (Ed Note: This is a distinct possibility) the party becomes about an even-money bet to hold the House." (And then they'd almost certainly keep the Senate, too.)
Republicans ran this country into a ditch. Their candidates this year offer nothing but a return to the all government is bad, reducing taxes is always good, don't give the suckers an even break policies of the Bush Administration that led to the biggest deficits in history and a concentration of wealth matched only moments before the Great Depression, which was not a coincidence.
Volunteer, talk to your friends, post on your facebook, Get Out The Vote.