For Democrats in North Carolina this year the problem is not so much the voters turning against them, as whether they'll be able to get their folks out to the polls to the same extent fired up Republicans can this year.
Our last statewide poll found only 6% of people who supported Barack Obama for President planning to vote Republican for the legislature. That's not a particularly large number, and it's basically indistinguishable from the 4% of McCain supporters who say they're going to vote Democratic this year.
There aren't enough one time Democratic voters abandoning ship to allow Republicans to take the legislature this year. If the folks who turn out this November mirror the folks who turned out in November 2008 there's little doubt Marc Basnight and Joe Hackney will still be running their chambers a year from now.
The problem for Democrats- as it was in the recent elections in Massachusetts and particularly Virginia- is that Republican voters are a lot more excited about coming out to vote this year. Where 11% more Democrats than Republicans voted in North Carolina in 2008, at this point only 6% more Democrats than Republicans are planning to vote in 2010. That may not seem like a huge change but it's certainly enough to flip a lot of close races.
The vast majority of people who supported Democratic candidates in 2008 will do so this year, but the party will have to figure out how to convince its comparatively disengaged voters to get out to the polls. Republicans could end up having a big year in the state not so much because 2008 Democratic voters turn away from the party, but because they end up just doing nothing this year.