Races are ranked in order of their likelihood of changing parties by November 2010, accounting for all factors such as potential retirements, primary challenges, and so forth.
Likelihood of party switch has increased since last month‘s rankings.
Likelihood of party switch has decreased since last month.
1. 
New Hampshire (R-Open)
New Hampshire rotates back into the top spot that it previously occupied in February, as 1st District Congresswoman Carol Shea-Porter now says she won’t run for the seat, which leaves her colleague from the 2nd District, Paul Hodes, with an unobstructed path to the Democratic nomination. Meanwhile, an ARG poll (yes, it’s ARG) gives Hodes a 6-point lead over former Senator John Sununu, who has yet to declare his interest in the race. This race won’t be any cakewalk, but the fundamentals — open seat in an Obama state where the Democratic nominee has a big head start — bode well for Team Blue.
2. Pennsylvania (R-Specter)
There’s been some contradictory polling in Pennsylvania, with Quinnipiac placing conservative challenger Pat Toomey, who would be a heavy underdog in the general election, 14 points ahead of Arlen Specter. Franklin and Marshall, meanwhile, gives Specter a 15-point lead. I don’t know that there’s any a priori way to say which poll is correct. Polling primaries is intrinsically pretty difficult, and polling races more than a year in advance is intrinsically pretty difficult, which means that polling primaries a year in advance is really difficult. If you simply average the two numbers, you get the Republican primary being a toss-up. Each of these polls, it should be noted, were taken before Specter’s intention to vote against the Employee Free Choice Act became known to voters, a position which will presumably help him the primaries while probably harming him with Pennsylvania’s fairly union-friendly general electorate.
Let’s do some fuzzy math here. Assume that there is a 80 percent chance that Specter’s health is such that he chooses to run for re-election. If Specter runs for re-election, there is a50 percent chance that he survives the primary. If he survives the primary, there is a 80 percent chance that he wins the general election, where the Democratic opposition has been a bit disorganized. If he loses the primary, however, or chooses not to run, the Republican nominee (presumably Toomey) will probably only have about a 10 percent chance of retaining the seat for the Republicans. Run all the numbers, and that yields a 62 percent chance that the Democrats pick up the seat. Granted, it’s fairly dubious to imply any sort of precision when we’re dealing with guesstimates like these. But my impression is that the Democrats’ odds in New Hampshire, with Hodes now having the primary field to himself, are a just a touch better than that. Also, Specter’s nay vote on EFCA probably eliminates the chances of the Democrats picking this seat up through a party switch.
3. Missouri (R-Open)
I think we can characterize Robin Carnahan as the slight favorite when even Republican internal polling shows her with a small lead over the two most likely Republican opponents.
4. 
Kentucky (R-Bunning)
The next two races — Connecticut and Kentucky — have many surface similarities, with an extremely unpopular incumbent in what would ordinarily be considered a safe seat for their respective parties. I’m placing Jim Bunning slightly ahead because his senility is a more intractable issue than Dodd’s real and alleged misjudgments in the financial sector, which may blow over at least to some extent if the economy improves. Bunning also has a strong opponent in the form of Democratic Attorney General Jack Conway, who just declared for the race; Conway is one of several Democrats with a lead on Bunning in a new set of PPP polling (.pdf). Bunning, meanwhile, is having an awful time trying to raise money, something less likely to be a problem for Dodd, who is generally a superior fundraiser. And although a primary challenge to Bunning is possible, and perhaps even likely, PPP and Research 2000 polling do not show alternative Republican candidates doing particularly better.
5. 
Connecticut (D-Dodd)
That is not to suggest, however, that Democrats ought to feel much comfort in Connecticut, not when a Quinnipiac poll puts Dodd 16 (!) points behind GOP challenger Rob Simmons. Still, while I don’t doubt that Dodd would lose an election held today, he has a lot of time to regain his footing, whereas Bunning’s numbers have been bad for years. The other good news for Democrats is that they now have a likely primary challenger in Roger Pearson. Pearson, a former selectman from Greenwich, is a virtual unknown to most Connecticutians, but a generic Democrat is probably all it takes to hold the seat.
6. Ohio (R-Open)
Lieutenant Governor Lee Fisher raised a cool $1 million dollars last quarter, but there are no signs of détente with Secretary of State Jennifer Brunner, his primary primary opponent, whereas Rob Portman should cruise to the Republican nomination.
7. Florida (R-Open)
Florida has been much quieter than the other races, although Kendrick Meek, who is probably the leading Democratic candidate, had a rather strong fundraising quarter. We still need to hedge a bit, however, until we know whether Charlie Crist will enter the race, a contingency that I remain skeptical of, but which would bump this race’s ranking well into the double digits.
8. North Carolina (R-Burr)
Recruiting in North Carolina isn’t important just for Mike Krzyzewski and Roy Williams; it’s important for the Democrats too. A new Civitas poll puts Republican Richard Burr, who might be the least-recognized incumbent in the country, behind Democratic Attorney General Roy Cooper, who is well known for his intervention in the Duke lacrosse scandal. Cooper, however, has yet to declare for the race, and all other prospective Democratic candidates have trailed Burr in the polling.
9. 
Nevada (D-Reid)
I’m demoting this race slightly on the no-news-is-good-news principle, as Harry Reid has managed to stay somewhat out of the headlines (is Dodd’s trauma Reid’s gain?), whereas meanwhile the Republicans have gotten no closer to selecting a challenger. Reid is also aided by the fact that Governor Jim Gibbons is at least as unpopular as he is and is already drawing Republican primary heat that could conceivably otherwise have wound up in the Senate contest.
10. 
Colorado (D-Bennet)
This may sound a bit subjective, but pseudo-incumbent Michael Bennet seems awfully unsure of himself, waffling on EFCA and angering his party base by joining the Blue Dog Congress. Although Colorado is a purple state, it is not a moderate state in the same way that, say, Ohio is. Rather, it contains roughly equal numbers of rather progressive Democrats and rather conservative Republicans. Bennet risks squeezing himself by being too far to the right of the primary electorate, while still being too far to the left to placate religious conservatives in Colorado Springs and Grand Junction. Moreover, as he’s never run for public office before, there is no guarantee that he’ll prove to be a competent candidate. Colorado is the one state, aside from Connecticut, where Democrats could potentially improve their lot with a primary challenge.
11. 
Illinois (D-Burris)
Burris seems to have become slightly less radioactive over the past month. Still, the clear and present danger for Democrats is that he emerges victorious with a narrow plurality of the vote in a four- or five-way contested primary. On this front, there are some small nuggets of good news for the Democrats: Alexi Giannoulis had a pretty good fundraising month, possibly giving him a leg up on the field, whereas Lisa Madigan has her sights set on Springfield rather than Washington.
12. 
Delaware (D-Open)
Possible Republican nominee (and current Congressman) Mike Castle has an 8-point lead over probable Democratic nominee Beau Biden. To this point, there have been no tangible signs that Castle is interested in the race, and Biden’s approval ratings in the same poll were solid, but this is nevertheless a bit of a sleeper.
13. Texas (R-Open?)
Kay Bailey Hutchison’s probable gubernatorial challenge to Rick Perry, which could make for a quite interesting Senate contest, remains the (ahem!) worst-kept secret in electoral politics today.
14. Louisiana (R-Vitter)
David Vitter won’t face a primary challenge from Family Research Council president Tony Perkins, but he’d better hope this doesn’t show up on Youtube.
15. 
Arkansas (D-Lincoln)
A PPP poll has Blanche Lincoln with suddenly very marginal approval ratings. Democrats are fortunate that the Republican bench is rather weak in Arkansas (Mike Huckabee, from what I’ve been told, is exceptionally unlikely to enter). But if things break badly for Lincoln in this red-trending state, even a generic Republican opponent might become competitive with her.
16. New York (Jr.) (D-Gillibrand)
Kirsten Gillibrand owes David Patterson twice over. Not only did he name her to the Senate, but he made himself so unpopular in the process that most of the serious opposition will probably gravitate toward his race rather than to Gillibrand’s. Meanwhile, although Gillibrand’s approval ratings are tepid, her fundraising has been hot, hot, hot.
17. Wisconsin (D-Feingold)
18. Iowa (R-Grassley)
19.
California (D-Boxer)
The Governator isn’t running. Carly Fiornia might, but there’s no evidence that she’s ever sold particularly well to the public.
20. Arizona (R-McCain)
21. Kansas (R-Open)
22. Oklahoma (R-Coburn)
23. Hawaii (D-Inoyue)
24. Georgia (R-Isakson)
25. 
Alaska (R-Murkowski)
Sarah Palin and Lisa Murkowski are now BFF, probably ending the Democrats’ slim chances of picking up this seat via some sort of mutually-assured destruction.
26. North Dakota (D-Dorgan)
27. Maryland (D-Mikulski)
28. South Carolina (R-DeMint)
29. Washington (D-Murray)
30. South Dakota (R-Thune)
31. 
Indiana (D-Bayh)
Republicans seem to have no interest whatsoever in challenging Bayh. Hmm, wonder why that is?
32. Vermont (D-Leahy)
33. Oregon (D-Wyden)
34. Alabama (R-Shelby)
35. Utah (R-Bennett)
36. New York (Sr.) (D-Schumer)
37. Idaho (R-Crapo)