John Judis has a rundown of the 2008 Senate races, noting that in the long run Warner leaving is a lot more important than Craig’s resignation. I agree that the Dems are very, very likely to win Colorado and New Hampshire. The most interesting category to me is the “could win” one:
Moderate Republican incumbents Norm Coleman in Minnesota, Susan Collins in Maine, and Gordon Smith in Oregon could be in trouble because they are running in states that are expected to vote strongly Democratic in 2008. If the Iraq war drags on, and the Republicans are identified nationally with it, these candidates will have to run against their own party. Coleman and Smith are both unpopular in their states but face relatively inexperienced, although by no means incapable, foes. Collins remains popular in Maine, but she faces a popular Democratic congressman, Tom Allen. These races could hinge on voter disgust with the national Republicans and who runs the best campaigns.
Here, I’m a touch less optimistic. I’ll be interested to see how Allen looks; I’ve generally assumed that, while GOP control of the seats will end with the end of their tenures, that Snowe and Collins have their seats for as long as they want them. I’d be pretty skeptical about Democratic chances there. Minnesota seems the most promising. I don’t know what to make of Oregon; it seems like a good pickup theory in principle, but Smith seems oddly popular. (I would definitely like to see his “disapprove” numbers get over 50% before I’ll be too optimistic…)
The bottom line, I guess, is that while the Dems are in good shape because they have a lot of opportunities for states where things can break right, we shouldn’t forget how hard it is to beat a GOP incumbent even in a blue state. This is why Warner resigning helps a lot. I would be surprised if the Dems could pick off more than 1 of the above three incumbents, and I wouldn’t be shocked if they all held on.