These things are all the rage now, so we thought we'd take a stab...seats are ranked in order of likelihood of flipping.
Obviously, these rankings are a snapshot in time, and subject to change.
1. Kentucky-Bunning (R) incumbent. Yeah, he's an incumbent. That's the whole reason the race ranks where it does.
Bunning, if he is renominated, is this year's answer to Rick Santorum. And at the moment, it looks quite a lot like he will be renominated. The Republicans don't look set to primary him (although I'm sure they'd like to), since the strongest candidate in the pool, Secretary of State Trey Grayson, won't run for the seat unless Bunning doesn't run.
The Democrats have two strong candidates in the race, with Attorney General Jack Conway enjoying particularly strong polling numbers (currently he is polling ahead of Grayson).
A lot could change - Bunning could still retire, which would drop this race considerably. But right now, we feel that Democrats have a better chance of beating Bunning than taking any open seat.
- Missouri-OPEN: Bond (R) Yes, this is a controversial selection, since everybody likes New Hampshire more than this race.
Missouri ranks second, however, for the following reasons. Democrats have an exceptional candidate with statewide name recognition (and a particularly famous last name), Robin Carnahan. Republicans have a controversial candidate with high name recognition (and high negatives), Roy Blunt. He also has a famous last name, as his son was a wildly unpopular Governor, and his wife and children are lobbyists (which will not go over well).
Blunt's first-quarter fundraising was pretty lame, and there are already concerns from within the GOP about his chances.
3. New Hampshire-OPEN: Gregg (R). The consensus number 1 or 2 pick is our Number 3. We agree that it's got a fairly good chance of flipping, with Democratic Rep. Paul Hodes in the Senate race already.
Hodes' Q1 fundraising wasn't stellar, but he's got a head start in that regard, and there isn't a lot of talent in the New Hampshire GOP to take him on at the moment. Defeated Senator John E. Sununu is one potential candidate, as is the man Hodes defeated in 2006, former Rep. Charlie Bass.
Both could be decent statewide candidates, and perhaps beat Hodes if the 2010 climate is favorable enough for Republicans, but given the recent Democratic trend in New Hampshire, the party ought to feel pretty good about this one.
4. Ohio-OPEN: Voinovich (R). Pennsylvania is a popular choice for the third position on many lists, given the fairly high probability that incumbent Repub Arlen Specter will lose a primary election to right-winger Pat Toomey, essentially gifting the seat to the Democrats.
We picked Ohio third for the moment since Specter is still standing, and there's at least a chance that he does survive the primary.
The Ohio race pits a couple of fairly strong Dems, Lee Fisher and Jennifer Brunner, against a fairly strong Republican, former Congressman, OMB Director and US Trade Representative Rob Portman. Portman's fundraising has been very good, but he has trailed fairly consistently in polling, and lacks the statewide base that Fisher and Brunner have.
This race is a tossup, but polling says it has a good chance of flipping.
5. Pennsylvania-Specter(R) incumbent. As noted this morning, Specter trails badly in a primary matchup against former Club for Growth president Pat Toomey.
Specter could probably win the election if he could get out of the primary...but that's currently looking pretty tough for him.
He might be able to eke out a win if he ran as an independent, however.
6. Connecticut-Dodd (D) incumbent. Dodd is actually weaker for the general election than Specter is. However, Dodd has the good fortune of not facing a primary challenge (at least not now), and it would take a pretty impressive Democrat to knock off Dodd in a primary.
Dodd's decline in fortunes have been well publicized, but he remains a strong fundraiser, and ought to have the support of the administration and the DSCC as he runs for reelection in a solidly blue state.
That's not to say he is going to win reelection - things do not look good for him right now, not at all - but he's got a shot. If the economy picks up a bit between now and November 2010, that should only help him.
7. North Carolina-Burr (R) incumbent. Democrats are actually very bullish on their chances of beating Burr, and with good reason; he's currently polling four points below North Carolina's popular Attorney General, Roy Cooper.
Burr is a solidly conservative Senator in a state that just voted for Obama, along with Sen. Kay Hagan and Governor Bev Perdue. He has a limited record of accomplishment in the Senate, and Democrats have a strong field of candidates ready to take him on, with Cooper the most prominent.
Burr merits a slight edge for now, being the incumbent in a relatively Republican-friendly state, but that's certainly subject to change.
8. Colorado-Bennet (D) incumbent. Bennet isn't that widely known, nor is he wildly popular at the moment among those who have formed an opinion.
Fortunately for Bennet, his potential Republican opponents aren't faring so well in polling, either.
Bennet still has to get past a possible Democratic primary (House Speaker Andrew Romanoff is one potential candidate), and should have a fairly close election if he does. Still, he's got the better part of two years to raise his profile - and his favorables.
9. Florida-OPEN: Martinez (R). This is the lowest-ranked "competitive" open seat, due to the possibility that popular Republican Gov. Charlie Crist might enter the Senate race.
Crist would be a formidable candidate in the general election, and would make a pretty tough race for either Democratic candidate (Rep. Kendrick Meek and State Sen. Dan Gelber). As a moderate Republican, however, it's possible Crist could get a serious primary challenge, which would make things a lot more interesting.
If Crist doesn't enter the race, things look considerably easier for both Democrats. If he does, this race drops a few slots.
10. Louisiana-Vitter (R) incumbent. Diaper Dave's rather notorious involvement in the D.C. madam scandal affected his polling numbers rather adversely.
We don't know who's going to run against him, but it should be a moderately competitive race. This is certainly a likely Republican hold, but it's a viable race for the Democrats.
11. Nevada-Reid (D) incumbent. There was a time when Reid was the most endangered Democrat, but circumstances have changed. Former Rep. Jon Porter has gone to K Street, Rep. Dean Heller and former state Sen. Joe Heck are looking at Carson City and the Governor's mansion, and Lieutenant Governor Brian Krolicki is under indictment.
This leaves former Club For Growth darling Sharron Angle and imported Wall Street exec John "Chachi" Chachas as the chief pretenders. Not an inspiring pool for the GOP, for what would be a winnable race.
12. Arkansas-Lincoln (D) incumbent. Initially this did not look like it would be much of a race, as Lincoln is a two-term incumbent, and there isn't much talent in the Arkansas Republican Party, which didn't even field a challenge to junior Sen. Mark Pryor in 2008.
However, a couple of second-tier candidates are polling fairly well against Lincoln, indicating there might be genuine cause for concern here.
13. Illinois-Burris (D) incumbent. Roland Burris thinks Roland Burris is great news for Roland Burris, but no one else does. Fortunately, Roland Burris probably won't be the candidate next fall.
The Illinois GOP is at its lowest ebb at the moment, but they have one guy in the field who could make this quite a race, U.S. Rep. Mark Kirk. This race will jump a few spots if and when Kirk does get in.
Other races to watch:
Alaska-Murkowski (R) incumbent. It would take an exceptional candidate and campaign to make this competitive.
Arizona-McCain (R) incumbent. McCain should be just fine unless someone manages to torpedo him in a Republican primary, which is perhaps not completely out of the realm of possibility.
California-Boxer (D) incumbent. The California GOP is in worse condition now than they've been in decades after Obama ran riot, electorally speaking, in California, picking up 61% of the vote. Still, no place to go but up, right?
Delaware-OPEN: Kaufman (D). This race would be one of the most competitive in the country, instantly, if Republican Rep. Mike Castle runs. At the moment, it's looking like he might, although no one knows, including Castle himself. Heck, he could retire altogether for all anyone knows (he's 70 years old).
We'll reevaluate this one if Castle runs, but without Castle, it should be a fairly easy Democratic hold.
Iowa-Grassley (R) incumbent. Grassley is apparently figuring on getting a primary challenge. Any Democrat would have a tough time beating him, but if he gets torpedoed in the primary, it's a whole new ballgame.
Kansas-OPEN: Brownback (R). No Sebelius and no Gov. Mark Parkinson in the race, and one of the toughest states for a Democrat in the entire country. It's an open seat, but...
New York-Gillibrand (D) incumbent. Maybe this seat's in real danger of flipping, but it looks pretty safe for now. If the GOP gets former New York Gov. George Pataki to run, this might be more competitive, but even then, it's a tough race for Republicans. After all, Pataki left office with approval ratings worse than Eliot Spitzer's when he left office.
North Dakota-Dorgan (D) incumbent. Take the Delaware comment and substitute Gov. John Hoeven for Rep. Mike Castle, and you've got a similar situation.
One big difference: Hoeven trails Dorgan, badly, in polling.
Oklahoma-Coburn (R) incumbent. He might retire, or do any number of bizarre things. It's Tom Coburn.
Texas-OPEN (sort of): Hutchison (R). This race would rank higher if it existed, but at the moment, it doesn't. We're waiting for a retirement from KayBee, which we may not get until she is elected Governor.
Wisconsin-Feingold (D) incumbent. He should be OK, but it's certainly possible for the GOP to throw a good scare into him. He's won three elections, but has maxed out (so far) at 55% of the vote.