CQ has the rundown here. Of course, these things are inherently a little fuzzy. Parties experience waves of support now and again driven by large macro-political events. And good candidates waging good campaigns can win “unwinnable” races against representatives of an unpopular national party. I’ve seen a lot of analysis over the past year and a half indicating that Democrats underplayed their hand in the 2006 House races. There were a few dozen races, basically, where had there been enough funds for an adequate final-week push, you’d have won a couple handsful of ‘em.
The overall political climate for 2008, meanwhile, shows overall signs of being just as bad for Republicans as you saw in 2006. The one fly in the ointment is that the existence of a presidential race alongside the congressional ones could prompt people’s most partisan pro-Republican instincts no matter how disgruntled they may be. At any rate, all this is by way of mentioning that I saw Dan Grant yesterday again, a great guy and a veteran of civilian-side operations in Kosovo, Iraq, and Afghanistan who’s running for congress in the Texas 10 against an undistinguished incumbent opponent. It’s not a CQ-certified competitive district and probably shouldn’t be. But these are the kind of races you can win if there’s a wave, and they’re also the kind of races of which a wave of victories is made.