• Arizona — Jon Kyl (OPEN) (R): Lean R

Sen. Jon Kyl's retirement creates what, on paper, looks like a pickup opportunity for the Democrats with the right person, in a state that's on the cusp between red and swingy. The jury's still out, though, on whether Richard Carmona, a former surgeon general under George W. Bush, is that guy or not. A few polls have found him within mid-single-digits of Rep. Jeff Flake—the all-but-certain Republican nominee—though a more recent poll by PPP had him further back. Also, before he can even think about Flake, Carmona first has to make it past Don Bivens, the former state party chair, in the Democratic primary. (DJ)

• California — Dianne Feinstein (D): Safe D

Even if the Republicans had managed to cough up a random rich guy, this would be a safely Democratic race, given not just California's distinctly blue hue but also Sen. Dianne Feinstein's staying power and warchest. Heck, even if the Republicans had managed to cajole one of the big names from their House delegation, it'd still be safe for Feinstein (and Lord knows they tried, particularly with Rep. David Dreier, who had nothing else to do after redistricting vaporized his seat). Instead, though, the two biggest names in the Republican field are establishment pick Elizabeth Emken (a former executive at the charity Autism Speaks) and the decidedly non-establishment dentist/attorney/birther queen Orly Taitz. (DJ)

• Connecticut — Joe Lieberman (OPEN) (I) : Lean D

The netroots wanted so badly to force Sen. Joe Lieberman into retirement. Alas, he reached for the rip-cord himself, leaving a seat that (in a presidential election year) ought to lean to the Democrats. The consensus is that Rep. Chris Murphy is the betting favorite in both the Democratic primary and general election. Republicans will choose between "moderate" former Rep. Chris Shays and conservative 2010 nominee Linda McMahon, who can swamp the race with her own money. (SS)

• Delaware — Tom Carper (D): Safe D

Delaware Republicans tipped their hand here by proclaiming they would have "real people" seeking the gubernatorial and senatorial seats here. Translation: Some Dudes. In the case of an opponent for two-term Sen. Tom Carper, that means Kevin Wade, who briefly sought the state's open House seat in 2010 before dropping out. Carper is sitting on $2.03 million, and Wade is $60,000 in debt. You do the math. (SS)

• Florida — Bill Nelson (D): Tossup

While we're of the opinion that two-term Democratic incumbent Sen. Bill Nelson has a slight advantage in his reelection campaign, Republicans landed a brand-name recruit in Rep. Connie Mack IV, and that's enough for us to position this race in the tossup column for now. Most of the polling has shown a tight race between Nelson and Mack, but Democrats should be encouraged by the fact that Mack is absorbing some serious blows from his chief primary rival, ex-Sen. George LeMieux, on character issues. LeMieux calls Mack "the Charlie Sheen of Florida politics" due to his history of bar brawls and tax liens, but with any luck, he'll turn out to be the Jaws IV of Macks. (JL)

• Hawaii — OPEN (Dan Akaka) (D): Lean D

The fundamentals of this race point to an easy Democratic hold: Hawaii is a deep blue state on the local level, and native son Barack Obama, who racked up an extraordinary 45-point win in 2008, will be on the ballot yet again this fall. But Republicans landed the one recruit who could make this race interesting, ex-Gov. Linda Lingle, while Democrats are dealing with a primary between Rep. Mazie Hirono and ex-Rep. Ed Case that threatens to turn ugly thanks to Case's shenanigans. What's more, polling has been truly all over the place, with Lingle even leading in some matchups. That's made us reluctant to call this race anything safer than Lean D at the moment. (DN)

• Indiana — Richard Lugar (R): Likely R

There's a pretty big condition precedent for our race rating of Indiana: Embattled GOP Sen. Richard Lugar must win his primary against tea-flavored state Treasurer Richard Mourdock. And Lugar, who's currently enduring some fairly embarrassing headlines on his out-of-state residency situation, certainly appears to have his hands full. If Mourdock can knock Lugar off—something recent polling suggests could definitely be in the cards—expect Democratic Rep. Joe Donnelly to make this race competitive. However, a new Donnelly internal put Lugar at just 42 percent in a head-to-head, suggesting that we might need to revisit this rating even if the incumbent gets renominated. (JL)

• Maine — Olympia Snowe (OPEN) (R): Tossup

Sen. Olympia Snowe's unexpected decision to retire just weeks ago has created one of the most bizarre political scenarios in recent times. The quick decision of independent former Gov. Angus King to seek the seat led to an odd paralysis on the Democratic side: The three most prominent Democrats in the picture (Rep. Chellie Pingree, Rep. Mike Michaud and ex-Gov. John Baldacci) all demurred, leaving King as the most prominent left-leaning candidate in the field. The problem? He's sending absurdly mixed signals, in one breath saying he'd vote for Barack Obama for president, yet in the next saying that he can envision caucusing with the GOP. While the DSCC has sent tacit signals that it might support King, until this race shakes out, it is hard to call it anything other than a tossup. (SS)

• Maryland — Ben Cardin (D): Safe D

Freshman Sen. Ben Cardin faced a decently competitive race against then-Lt. Gov. Michael Steele when this seat was open six years ago. This time, Maryland Republicans have produced a crop of D-list scrubs, and the filing deadline closed long ago. (DN)

• Massachusetts — Scott Brown (R): Tossup

There have been three phases of polling in this race so far. Phase 1 showed big leads for Sen. Scott Brown. Phase 2 showed slim leads for Democrat Elizabeth Warren. Phase 3 showed a few moderate Brown leads, which has led to a bit of handwringing and gnashing of teeth. Still, the dynamics of the race really haven't changed. Brown is quite personally popular in a state that generally likes incumbents, though he is prone to the occasional dumb statement or vote, and is not particularly accomplished legislator. Warren is an exceptionally talented challenger, in terms of fundraising, messaging, and the excitement she generates; she'd destroy a lesser Republican. Massachusetts is a solidly Democratic state and will give President Obama around 60 percent of the vote, but the state elected a series of Republican governors until 2006, so there has been a willingness to split tickets (at least in midterm elections) quite frequently. (AJ)

• Michigan — Debbie Stabenow (D): Lean D

National Republicans were thrilled to land 2010 gubernatorial candidate and ex-Rep. Pete Hoekstra to run against Sen. Debbie Stabenow, but I wonder how they're feeling now. Hoekstra initially appeared to have some real mojo, trailing Stabenow by only 1 percent in a December PPP poll (PDF). However, when Hoekstra released a "Super Bowl" ad cut by "master" GOP consultant Fred Davis, the blowback was pretty fierce after the commercial was widely panned for its jaw-droppingly racist portrayal of Asians. Stabenow is now breathing easier, enjoying 14 and 21-point leads over Hoekstra in the most recent polls. (JL)

• Minnesota — Amy Klobuchar (D): Safe D

Popular freshman Sen. Amy Klobuchar has had a fairly charmed political career so far, dismantling briefly-touted GOP Rep. Mark Kennedy with ease and grace in 2006, so it was always unlikely to see any credible Republicans mount a suicide run against her this year. Republicans recently thought they had a "rising star"-type candidate in Afghanistan vet Pete Hegseth, but the luster came off pretty quickly after it was revealed that he spent much of his time in college publishing incendiary columns in the Daily Princetonian, a student newspaper. Some other very minor hopefuls are also in the mix. Next! (JL)

• Mississippi — Roger Wicker (R): Safe R

Democrats took their best shot at Sen. Roger Wicker in 2008, putting significant resources behind the candidacy of ex-Gov. Ronnie Musgrove, but fell short by 10 percent. A November poll from PPP showed Wicker with commanding leads over "best hope" Democratic challengers (none of whom actually decided to run), but at least Team Blue did manage to snag a candidate with strong name recognition: Al Gore! (Unfortunately, that's possible octogenarian Al Gore, a retired army colonel and Methodist minister of no verifiable relation to the former vice president, though possessing a rather impressive military record.) (JL)

• Missouri — Claire McCaskill (D): Tossup

It's not hard to make the argument that freshman Sen. Claire McCaskill is the single most-endangered Democrat up for reelection this cycle. She's running in a red state that's generally grown quite hostile to national Democrats, and third-party conservative groups are gunning for her hard, having already spent a fortune on negative ads and with the promise of much more to come. What's more, even though Barack Obama rather improbably almost won the state in 2008, he doesn't look like he's planning to contest it this year. However, McCaskill is a vigorous campaigner and strong fundraiser, though her strongest asset may be the almost embarrassingly awful GOP field. This race could very well wind up tilting Republican by the end, but for now, we're regarding it as a Tossup. (DN)

• Montana — Jon Tester (D): Tossup

It's been clear for the last five years that the Montana seat—won narrowly by Jon Tester over long-time Republican incumbent Conrad Burns against the backdrop of the 2006 wave and corruption allegations against Burns—was going to be one of the toughest 2012 races for the Democrats. The state's Republican at-large representative, Denny Rehberg, is going for the promotion against the freshman Tester, but Tester's tough-guy profile and prairie populism are a good fit for the state, and he has a fighting chance here. Almost every poll has had Tester and Rehberg within a few points of each other. (DJ)

• Nebraska — Ben Nelson (OPEN) (D): Likely R

This race was going to be an extremely difficult hold even if Sen. Ben Nelson had sought reelection, and while Democrats got their best possible replacement candidate in the form of ex-Sen. Bob Kerrey, Republicans are still strongly favored in this dark-red state. Kerrey, of course, would not have entered the race if he didn't think he had a path to victory, though an awful lot of things would have to go exactly right for him to pull off an upset win. Kerrey's biggest advantage is the GOP's weak crop of candidates, but no matter whom Republicans nominate, they have the decided edge. (DN)

• Nevada — Dean Heller (R): Tossup

Multiple polls affirm that this is one of the best pickup opportunities the Democrats have nationwide. Sen. Dean Heller is an appointed incumbent, who is still little known in Clark County, where two thirds of the state's votes are cast. Democrats, meanwhile, counter with a familiar face in the Vegas metro area: Rep. Shelley Berkley, who has represented the region for nearly 15 years. Both the polling and the fundraising have been tight, and this should be a serious fight to the finish. (SS)

• New Jersey — Bob Menendez (D): Likely D

Freshman Sen. Bob Menendez earned his first term in 2006 with a solid-but-not-dominant 53-44 win over Tom Kean, Jr. This time around, he will face either state Sen. Joe Kyrillos or tea party favorite (and 2010 House candidate) Anna Little. Polls have been a mixed bag for Menendez—his approval numbers are purely "meh," but he has solid leads over both Kyrillos or Little. However, he's consistently under 50 percent, suggesting that this race could conceivably tighten with better name recognition for his Republican suitors. But New Jersey has long been fool's gold for Republicans, who haven't won a Senate race in the state since 1972. (SS)

• New Mexico — Jeff Bingaman (OPEN) (D): Tossup

In theory, the open seat Senate showdown here in the Land of Enchantment should lean Democratic, especially in a presidential year, but polls show a competitive contest. Former Republican Rep. Heather Wilson chased her toughest primary challenger (Lt. Gov. John Sanchez) from the race, while Rep. Martin Heinrich, though still the favorite to emerge as the Democratic nominee, still has to contend with Auditor Hector Balderas. Heinrich probably has a slight advantage over Wilson, but for now, we're calling it a Tossup. (SS)

• New York — Kirsten Gillibrand (D): Safe D

Even though she won the special election for the remainder of Hillary Clinton's term by a punishing 62-35 margin—in 2010, no less—New York Republicans are still delusional enough to think they can defeat Sen. Kirsten Gillibrand. They won't. (DN)

• North Dakota — Kent Conrad (OPEN) (D): Lean R

Democrats landed their strongest possible recruit in the wake of Sen. Kent Conrad's retirement, former state AG Heidi Heitkamp. She's won statewide several times, and though she lost the 2000 governor's race, she had to suspend her campaign to be treated for breast cancer in the final month, and still only lost by 11 points—while Al Gore was getting creamed by 27. Republicans have coalesced around freshman Rep. Rick Berg, but movement conservatives appear to mistrust him. The state's demographics still favor Berg, but the one unanswered poll of this race (from the DSCC) actually showed Heitkamp leading, and national Democrats won't let this one go without a fight. This could well be a Tossup before long. (DN)

• Ohio — Sherrod Brown (D): Lean D

Freshman Sen. Sherrod Brown, a populist hero, has been doing everything right so far in his bid for a second term, and the polling proves it—even though he's been the No. 1 target of conservative third-party attack ads in the nation. While most expect state Treasurer Josh Mandel to spark a closer race at some point, we're still waiting for that to happen. At the very start of the cycle, you'd have easily figured Brown would be one of the most at-risk Democrats up for reelection, but for now at least, he's got the edge here. (JL)

• Pennsylvania — Bob Casey (D): Likely D

Sen. Bob Casey's story is superficially similar to that of his neighbor, New Jersey's Bob Menendez. His job approval and favorability numbers are just okay, but the Republican field chasing him is ill-defined and unknown. Right-wing former state Rep. Sam Rohrer seems to be the popular choice, though some of the state's bigwigs (including Gov. Tom Corbett) have a preference for businessman Steven Welch. Unlike Menendez, though, Casey scored a dominant win (over Rick Santorum) in 2006 and comes from a well-known political family. He'll be very hard to beat this year. (SS)

• Rhode Island — Sheldon Whitehouse (D): Safe D

Freshman Sen. Sheldon Whitehouse hasn't done anything particularly controversial, and his likely opponent, Barry Hinckley, has earned most of his headlines so far for an incredibly awkward Fox News appearance. Hinckley has some money, so he's more than a generic Some Dude, but it will take a lot more than that to put this seat in play. The last poll seen shows Whitehouse up 22 points, which seems about right. After all, it's Rhode Island, in a presidential election year. (Incidentally, has there ever been a candidate with a better political name than "Whitehouse," matched up against a candidate with a more unfortunate political name than "Hinckley"?) (AJ)

• Tennessee — Bob Corker (R): Safe R

Given how badly Democrats have fared in Tennessee as of late, Harold Ford, Jr.'s narrow loss to Bob Corker in 2006 was kind of a remarkable achievement (as much of a wanker as Ford is). We're not likely to see a repeat of that barnburner of a race this year, though. The last we heard, local Democrats were casting about for "nontraditional options" to field against Corker. (JL)

• Texas — OPEN (Kay Bailey Hutchison): Safe R

It pains us to rate an open seat race as Safe R—even in a state as red as Texas, but that's where we are today. Democrats had initially touted the candidacy of retired General Ricardo Sanchez for the seat, but he pulled the plug on his campaign after enduring fundraising difficulties, problems with his baggage concerning Abu Ghraib (he was U.S. commander in Iraq when the prison scandal went down), and a fire which burned down his house. While several Democrats have since stepped up for Team Blue, including ex-state Rep. Paul Sadler, the reality is that the resources and money aren't on the table to make this race competitive. (JL)

• Utah — Orrin Hatch (R): RTW

Sen. Orrin Hatch has drawn a credible opponent for the Republican nomination in the form of ex-state Sen. Dan Liljenquist, and state Rep. Chris Herrod is also in the race. And thanks to Utah's unusual system of making candidates run the gauntlet before state convention delegates before they're even permitted to participate in the primary, an apostate like Hatch could find himself in trouble before this ultra-conservative tribal council—which is how Sen. Bob Bennett got turfed last cycle. But Hatch has learned from Bennett's mistakes and so far seems to be out-foxing his challengers. Still, the convention is unpollable and anything can happen, making this a Race to Watch. Whoever emerges with the GOP nod will be the victor in November, as Democrats in Utah are a long way from running competitively statewide. (DN)

• Vermont — Bernie Sanders (I): Safe I

The good news is, the Republicans have a candidate against freshman Sen. Bernie Sanders, and an actual former elected official, to boot! The bad news is, that candidate, John MacGovern, was elected to the state house of Massachusetts. Twenty years ago. But hey, beggars can't be choosers. Sanders has won statewide election every cycle since 1990, and hasn't faced a particularly serious challenge in eons. There's little reason to think he'll have one now. (AJ)

• Virginia — Jim Webb (OPEN) (D): Tossup

Polling has consistently shown an extremely close race between ex-Gov. Tim Kaine and ex-Gov./Sen. George Allen, two heavyweights of Virginia politics. Kaine has had the fundraising edge, though Allen certainly won't lack for resources (and some backers have even created a single-purpose super PAC to buttress him). Ultimately, though, Barack Obama's coattails may be what decides the day. We'll be watching this swing state very closely. (JL)

• Washington — Maria Cantwell (D): Likely D

Two-term Sen. Maria Cantwell has solid approval ratings and lives in a state where Republicans can often come close statewide but rarely are able to get over the top. There's little reason to think she's in danger, though she did draw a plausible opponent in the form of up-and-coming Republican state Sen. Michael Baumgartner. Two strikes against him, though, are that he's probably too conservative for the state as a whole, and that he's from the Spokane area; eastern Washington hasn't given the state a governor or senator since the 1930s. Cantwell has led early polls in the low double-digits. (DJ)

• West Virginia — Joe Manchin (D): Likely D

West Virginia ain't what it used to be for Democrats, especially Barack Obama. On the other hand, Joe Manchin is still popular. And, as the saying goes, you can't beat someone with no one ... and no one's a bigger "no one" than three-time loser John Raese, who managed to fall to Manchin by double digits in 2010, the best political climate for Republicans since the infamous landslide election of A.D. 686. Sure, Raese has some money, but he's also old, eccentric, doesn't really live in the state, and, well, never wins elections. (AJ)

• Wisconsin — OPEN: Tossup

Former governor and HHS Secretary Tommy Thompson is neither loved nor loathed, and he may lose his primary to former Rep. Mark Neumann (or, less likely, to state House Speaker Jeff Fitzgerald). On the flip side, Democratic Rep. Tammy Baldwin isn't yet that well-known. This is Wisconsin, which is generally closely contested at the presidential and statewide levels; it may have a very slight Democratic lean, but it's not something you want to bank on. Thompson's "moderate" record makes him the most electable Republican, so if he can't win his party's nod, that's a positive for Baldwin—though Neumann is rich as Croesus. (AJ)

• Wyoming — John Barrasso (R): Safe R

Did you know that Wyoming has a senator named John Barrasso? Chances are you didn't, and chances are that you won't hear much more about him in the coming months. Wyoming is one of the nation's reddest states, Barrasso has some of the nation's highest approval ratings of any senator, and he hasn't done anything unusual that would make him a target. No Democratic candidate has emerged yet. (DJ)