The "enthusiasm gap" between Republicans and Democrats is considered one of the biggest advantages that Republicans have going in to the midterm elections. Basically, Republicans are organized and motivated, while the Democratic base is just sorta bummin' and not expected to come out in full force.
Lacking a clear platform to rally around and basically trying to avoid debating the issues, Democrats don't seem to have a viable strategy to address this deficit. However, if health care, Wall Street reform and other Obama victories can't get Democrats motivated, there's still the possibility that the thought of Tea Partiers in Washington will scare progressives to the polls.
To that end, film maker Bill Simmon put together this short film called "Everyone Loses," showing images of Sarah Palin, Glenn Beck, Christine O'Donnell, Rand Paul and others to a soundtrack of "America the Beautiful." It leads with a photo of a Tea Partier with a sign that reads "Get a Brain Morans" and the caption "This guy's going to vote."
This may in fact be the best line of argument Democrats have to get the vote out. But that speaks volumes for the deep problems the party faces heading into November.