To defend against the potential for a Republican Senate, Democrats have five pickup opportunities of their own—albeit at greatly varying degrees of promise. Both parties say they will keep close tabs on Maine after Snowe's retirement; Democrats believe the front-runner, independent former Gov. Angus King, will caucus with them, while Republicans hold out hope that the eventual Democratic nominee catches fire and leaves their candidate vying to top a Democratic electorate divided between King and the nominee. National Democrats have made clear to their donors they back King.
After more than a month of bad press surrounding her self-reported Native American heritage, Democrats believe consumer advocate Elizabeth Warren has turned a corner. Sen. Scott Brown has made clear he has no intention of letting the matter drop as part of his strategy to drive up Warren's negative numbers. But Brown has to win over a huge number of Obama voters (Those undecided in the Senate race favor Obama over Romney by 30 to 40 points, according to both public and private surveys). Watch voter enthusiasm in this race; Warren already has an army of volunteers that will be difficult to match. Case in point: Her campaign held more than 50 canvassing events across the state last weekend—and it's only June.
Republican Sen. Dean Heller has established a clear, if slight, lead over Democratic Rep. Shelley Berkley in Nevada. Perhaps no other race is as tied to the presidential outcome as the Silver State's, where crossover voters are likely to be scarce (though one can envision an Obama-Heller voter better than a Romney-Berkley backer). A pending ethics investigation looms over Berkley's head, though her campaign has planned a paid and earned media response once the case is resolved.
Indiana and Arizona are Democrats' opportunities to expand the map, though in both races Republicans are the favorites. Sen. Dick Lugar's primary loss makes Indiana more competitive, even Republicans will admit, but they believe the state's tilt still benefits Richard Mourdock over Rep. Joe Donnelly (Democrats admit Donnelly must prove he can compete here before he gets outside help). And Rep. Jeff Flake is watching his opponent, businessman Wil Cardon, surge in the polls, though the GOP is confident that Obama's purported interest in turning Arizona purple is still a few years premature.
In total, the battle for the Senate is being fought mostly on the same turf it was at the beginning of the cycle. Democrats have recruited well in some additional states, broadening the map to a slight degree, but Republicans are by and large playing on friendly ground. With five months to go, that static reality means voters aren't going to repeat the dramatic swings to which we've become accustomed. The new normal, as it turns out, was little more than a three-cycle aberration.