PPP's latest poll shows Democrats winning self-described moderates 58-28:

The fact that Republicans are winning this election without showing much appeal to moderates is another reminder that the main reason for the pending GOP onslaught is the disengagement of Democratic voters. Conservatives will make up a much larger portion of the electorate this year than they did in 2008 and that's put Republicans in a position to make big gains without even having to develop a message that's appealing to the center.

That's the reason why this year's Republican resurgence may prove to be short lived and why much of what the party gains this year could be lost again in 2012. The formula they're using for victory this year- fire up the base, forget the moderates- may work for a midterm election but it's not likely to be particularly sustainable in a Presidential year. If Republicans want the 2012 election cycle to be as enjoyable for them as the 2010 cycle has been they have a lot of work to do to broaden their base.