Chris, I read your post below about the growing enthusiasm gap between Republicans and Democrats heading into the 2012 general election season. I thought it was an interesting stat to look at, but it's also worth pointing out that PPP is a left-leaning polling house. Their results (57-46 in favor of Democrats) paint a pretty different (read: lopsided) picture than Gallup's this week (46-43 in favor of Democrats).
Yes, Democrats are winning the enthusiasm gap... for now. I think this was pretty predictable. The GOP base is heavily divided at this point between conservative and moderate voters. With Romney all but sealing up the nomination at this point, I think it's fair to say that the conservative base is, er... less than enthused. But I'm thinking that the closer we get the election, the motivation to oust Obama from office will unite Republican voters and we'll see the statistics reflect it.
Call me crazy, but I still think it would be hard to dampen spirits to the point where the GOP could lose the edge on enthusiasm heading into November.
Obama certainly has momentum right now as Republicans still struggle to name their chosen contender. But with the Supreme Court set to weigh in on the president's signature health care overhaul, showing his true colors and disregard of the constitution will likely also motivate voters to the polls.
Overall, it's also important to note that neither party has come close to capturing the level of enthusiasm which propelled Obama to the White House in 2008.