Gallup:

In thinking about the 2012 presidential election, 45% of Democrats and independents who lean Democratic say they are more enthusiastic about voting than usual, while nearly as many, 44%, are less enthusiastic. This is in sharp contrast to 2008 and, to a lesser extent, 2004, when the great majority of Democrats expressed heightened enthusiasm about voting.

Democrats' muted response to voting in 2012 also contrasts with Republicans' eagerness. Nearly 6 in 10 Republicans, 58%, describe themselves as more enthusiastic about voting. That is nearly identical to Republicans' average level of enthusiasm in 2004 (59%) and higher than it was at most points in 2008.

The latest results are from a USA Today/Gallup poll conducted Sept. 15-18, nearly 14 months before the 2012 election is to be held. This is the earliest Gallup has asked Americans to rate their enthusiasm about voting in advance of a presidential election. All of the measures leading up to the 2000, 2004, and 2008 elections were conducted in the same calendar year, starting in January. Nevertheless, the robust level of Republican enthusiasm today suggests that Democrats' subdued enthusiasm is meaningful, rather than merely a reflection of the early timing.

I imagine that gap will widen before election day. Once it becomes clear that the Dems will not only probably lose the presidency but the senate as well, the gloom will be pretty thick. And Obama is likely to make more lurches toward the center on other issues that will further anger the far left. That too, will contribute to a depressed turnout for Dems.