Denny Rehberg and Jon Tester are tied in Montana. Crystal ball: Senate race projections

So here we are, approaching the finish line of the grueling two-year struggle for the U.S. Senate. And after all this — the hard-sell candidate recruiting, the hundreds of millions of dollars in attack ads, the countless debates and endless courting of elusive undecided voters — we’re likely to end up where we started: with Harry Reid leading a narrow Democratic majority.

In the final, crystal-ball edition of this election cycle’s Senate Monthly 10 — our rolling rankings of the most competitive races, in order from most to least difficult to predict — POLITICO forecasts Republican pickups in Nebraska and North Dakota and Democratic takeaways in Massachusetts and Maine.


After those, it gets dicier.

To take the Senate, the GOP needs to net four seats if President Barack Obama is reelected, or three if Mitt Romney wins.

But the 33-seat map has only a trifecta of genuinely tied races: Montana, Wisconsin and Indiana. Even if the GOP sweeps all three, the party would still need two more surprise wins elsewhere to take the Senate.

That’s unlikely to happen. Instead, we project a 53-47 Democratic Senate — the same makeup as now.

Here’s our top 10 list, with projected winners for each.

Review September’s ratings here.

1. Montana (up 1 spot)

It’s the race that has some of the wisest operatives hedging. While it has lacked the star power of Massachusetts or Virginia, there’s a real chance Montana could end up being the state that remains undecided Wednesday or sparks a recount, operatives on both sides warn. Rep. Denny Rehberg — who just released an ad featuring Romney — enjoys the benefit of amped-up party enthusiasm in a presidential year. Sen. Jon Tester has run something close to an operationally flawless campaign, sweeping the state’s newspaper endorsements — even in Rehberg’s hometown of Billings. A pesky libertarian candidate lingering in single digits could sway the outcome. There’s a reason Rehberg hasn’t closed the deal: It’s tough to beat an incumbent who fits his state like a glove and comes off as more likable.

POLITICO projection: Tester by 1 percent

Latest poll: Tester 48 percent, Rehberg 48 percent (Rasmussen Reports, 500 likely voters, Oct. 14)

2. Wisconsin (up 5 spots)

With more than $40 million spent, it’s the Badger State’s most expensive Senate race ever. And perhaps no other contest has had such volatile polling swings. Rep. Tammy Baldwin is a dyed-in-the-wool liberal whose campaign impressively repositioned her in the center for a general election. Tommy Thompson is an icon from another era who is trying to rekindle the magic as he’s burdened by his Washington baggage. Thompson doesn’t need the Romney-Ryan ticket to win Wisconsin; he just needs them to lose narrowly. The well-oiled GOP machine built to protect Gov. Scott Walker from recall should give the former four-term governor a slight edge.

POLITICO projection: Thompson by 2 percent

Latest poll: Baldwin 47 percent, Thompson 43 percent (Marquette Law School, 1,404 registered voters, Oct. 25-28)

3. Nevada (up 1 spot)

Once again, it’s Democratic pollster Mark Mellman vs. the world. The one man who called Harry Reid’s 2010 win is predicting history will repeat itself and the public polling will be wrong. There has been only one single public poll all year that has shown Democratic Rep. Shelley Berkley ahead of GOP Sen. Dean Heller. Democrats hold the party registration advantage, an early vote edge and will lean on the vaunted Reid machine. But Republicans convincingly note that Berkley is no Reid and Heller is no Sharron Angle. “Obama really has to overperform for her to win,” conceded a Washington-based Democratic strategist. Publicly, Heller’s team frames themselves as the underdogs; privately, they are one of the most confident campaigns in the country.

POLITICO projection: Heller by 2 percent

Latest poll: Heller 46 percent, Berkley 40 percent (Las Vegas Review-Journal/SurveyUSA, 1,212 likely voters, Oct. 23-29)

4. Indiana (up 1 spot)

The Hoosier State has the potential to be the Senate upset of the night. Republican Richard Mourdock’s late October debate comment suggesting that pregnancy from rape is “something that God intended to happen” has bolstered Rep. Joe Donnelly’s chances to steal the seat. Even Mourdock’s own internal polling shows he enters Election Day in a dead heat. What breaks the logjam? Republicans hope it’ll be the top of the ticket, where Romney could throttle Obama by as many as 15 points. But Mourdock’s misstep drew a torrent of bad press just as many voters were tuning in. And Democrats believe the anti-abortion, Blue Dog Donnelly is more in the tradition of ousted Sen. Dick Lugar than Mourdock.

POLITICO projection: Donnelly by 2 percent

Latest poll: Mourdock 47 percent, Donnelly 42 percent (Rasmussen Reports, 600 likely voters, Oct. 10-11)

5. Virginia (down 2 spots)

Perched at the top of our Senate ratings for most of the cycle, Virginia tumbles down the list as the race trends toward Tim Kaine. George Allen ran a safe, mostly mistake-free race, but his main argument tying Kaine to Obama seemed feckless in a state that may well vote to reelect the president. Kaine is also a superior candidate, whose bipartisan overtures and affable demeanor appear unpackaged and authentic. It’s no wonder the former Democratic National Committee chairman is on track to outperform the president in the commonwealth.

POLITICO projection: Kaine by 3 percent

Latest poll: Kaine 50 percent, Allen 46 percent (CBS/New York Times/Quinnipiac University, 1,074 likely voters, Oct. 23-28)

6. Massachusetts (down 5 spots)

Perhaps he could’ve hit Elizabeth Warren harder earlier. Or not signed the super PAC agreement that sidelined outside interests. Or decided to participate in the last debate. But in reality, it’s not clear what Sen. Scott Brown could’ve done differently in his premier battle with the liberal heroine and potential future presidential candidate. Warren, it turned out, was no Martha Coakley: The consumer crusader was formidable in debates, comfortable on the stump and prolific raising money. With a president who’s enormously popular in the Bay State atop the ticket, it all looks like too much for Brown to overcome.

POLITICO projection: Warren by 5 percent

Latest poll: Warren 53 percent, Brown 46 percent (Suffolk University, 600 likely voters, Oct. 25-28)

7. North Dakota (down 1 spot)

Like Scott Brown was for Republicans, Democrat Heidi Heitkamp might be the best losing candidate her party had to offer this year. Her ads were pitch perfect, her retail skills unmatched, her messaging fiercely disciplined. But also like the Massachusetts incumbent, Heitkamp is battling stiff presidential head winds in a state that overwhelmingly disapproves of the president’s signature piece of domestic legislation. Republican Rep. Rick Berg was far from the perfect candidate, but he’s picked up steam in recent weeks, putting Heitkamp on defense over her campaign contributions and forcing Democrats to take a much harsher tone on the airwaves.

POLITICO projection: Berg by 4 percent

Latest poll: Berg 47 percent, Heitkamp 45 percent (Mason-Dixon, 625 likely voters, Oct. 26-28)

8. Ohio (returning)

Sen. Sherrod Brown has heard the footsteps of Republican Josh Mandel creeping closer in the closing weeks. But the first-term Democrat has reacted with barely a shrug. Brown has complained that outside spending — now nearing $30 million — is the only reason Mandel is even in the game. Yet it’s Brown’s ads — combined with damaging in-state press coverage — that have left an impression with voters that the 35-year-old Mandel is overly ambitious and under-qualified.

POLITICO projection: Brown by 5 percent

Latest poll: Brown 49 percent, Mandel 44 percent (Ohio Poll/University of Cincinnati, 1,182 likely voters, Oct. 25-30)

9. Missouri (unchanged)

At the beginning of the cycle, Republicans had convinced themselves that Sen. Claire McCaskill was the one Democratic incumbent sure to lose. Now, a second term for the sharp-tongued Missouri moderate looks like all but a sure thing. Yes, she was blessed with the tone-deaf, gaffe-laden Rep. Todd Akin. But McCaskill’s deft political skills and tenacity should not be discounted. Due to Obama’s unpopularity in the state, a single-digit win seems most plausible. But any win at all would’ve been unimaginable just a few months ago.

POLITICO projection: McCaskill by 6 percent

Latest poll: McCaskill 45 percent, Akin 43 percent (St. Louis Post-Dispatch/Mason-Dixon, 625 likely voters, Oct. 23-25)

10. Florida (returning)

Perhaps Rep. Connie Mack should’ve stuck with his gut. The Fort Myers congressman had originally balked at a Senate run, citing family obligations, before changing his mind last October. Little has gone well since: Mack’s campaign has been marked by an unbecoming feud with the state’s most influential political reporter, paltry fundraising and a baffling focus on process and polls over substance. Democratic Sen. Bill Nelson, a bland and unoffensive figure, is threatened more by Romney’s performance than Mack’s firepower. But even a Romney victory here most likely won’t be enough for Mack to prevail.

POLITICO projection: Nelson by 8 percent

Latest poll: Nelson 50 percent, Mack 42 percent (Public Policy Polling, 687 likely voters, Oct. 26-28)