This article is from the archive of our partner National Journal

For Democrats to win back a Senate majority, the math is simple but the task is not: Win back five of the seven GOP-held seats in competitive states—and hold the two seats of their own that Republicans are contesting. Absent a wave election, they need to come close to running the table in the key races, and that means finding a slate of good candidates who run in a mistake-free fashion.

To be sure, Democrats have landed their strongest candidates in several crucial contests. In Ohio, they convinced former Gov. Ted Strickland to challenge Sen. Rob Portman—a contest that polls show is already competitive. They persuaded Rep. Tammy Duckworth to challenge Sen. Mark Kirk in Illinois. They convinced former Sen. Russ Feingold to go for a rematch bid against embattled Sen. Ron Johnson in Wisconsin. And to defend Harry Reid's must-win seat in Nevada, they landed a top-tier Hispanic recruit, former state Attorney General Catherine Cortez Masto.

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For a while, they appeared on track, but in the last month, the storm clouds have gathered. Former Sen. Kay Hagan of North Carolina opted not to run again for the Senate, leaving Democrats empty-handed as they seek a challenger against Sen. Richard Burr in the swing state. New Hampshire Gov. Maggie Hassan, who looked likely to challenge Sen. Kelly Ayotte, now appears to be hedging her bets in the midst of a tough budget battle with Republicans. Scandal-plagued Rep. Alan Grayson is taking on party favorite Rep. Patrick Murphy in Florida, and he's poised to spend millions damaging Murphy's image in the primary. Meanwhile, party concerns over former Rep. Joe Sestak continue unabated in Pennsylvania—with few alternative candidates looking to run. Even Strickland, despite leading in several polls, disappointed party officials with his underwhelming first two quarters of fundraising.

The Illinois and Wisconsin races are genuine toss-ups, with small advantages to the Democratic challengers. The Ohio Senate contest is looking highly competitive, but with an early GOP edge. But after those three opportunities, the pickings are now looking a lot tougher for the Democrats. Not only do they have to win all three of those toss-up races, but catch breaks in Pennsylvania, Florida, and New Hampshire in races that are looking less favorable—all while ensuring that they don't lose any momentum defending battleground seats in Nevada and Colorado.

It's still early, but those assessing whether Democrats can retake the majority can't ignore the four states where they've suffered setbacks. That's where the Democratic Senate majority will be made—or where it will fall apart.

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The best chance for Democrats to put another seat in play will come in New Hampshire, where Hassan is deciding whether to run for Senate or to pursue another term as governor. In a sign of the race's high stakes, outside Republican groups have already spent nearly $800,000 to tarnish Hassan's image after she vetoed a GOP-backed budget that would cut taxes and government spending. With the state's fiscal future hanging in the balance, some Hassan allies fear she'd risk being seen as irresponsible if she left to run a high-profile Senate race in the midst of a budgetary crisis. Her strong favorability numbers in the state—her main selling point for a Senate campaign—could easily drop once she launches her campaign. (Just ask the many Republican governors running for president.)

But one Democratic operative familiar with Hassan's thinking argued the attacks have made no difference in her decision to run—consistent with her plan all along. Republicans expect as much, too; they wouldn't be wasting valuable money in attack ads if they thought she wasn't interested. And if early polls showing a very close race between Ayotte and Hassan hold, New Hampshire would become a crucial battleground for the majority. Hassan's decision will be an important bellwether of her party's chances to retake control of the Senate. If she runs, Democrats would have four top-line nominees ready to challenge GOP senators. Without Hassan, there will be pressure for the party to nominate or recruit stronger candidates in the other battleground states.

It's a little more complicated in Pennsylvania, where Democrats are desperately looking to recruit an alternative to Sestak, whose unconventional campaign approach continues to worry party leaders. Even though divided primaries can be counterproductive, Democratic Senatorial Campaign Committee officials are feting Katie McGinty, Gov. Tom Wolf's chief of staff, in a belated effort to recruit her into the race. McGinty finished a distant fourth place in last year's Democratic gubernatorial primary, so it's a sign of Democratic urgency that they view her as a stronger alternative to Sestak. Party officials believe that recruiting a more reliable candidate with the ability to raise millions from women's groups is worth the risk of initiating a Democratic family feud. If she runs, the outcome of the intraparty battle will play a huge role in the party's chances of defeating GOP Sen. Pat Toomey.

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Meanwhile, a messy Democratic primary is already underway in Florida, where Democratic hopes of anointing Murphy as their nominee have gotten more challenging. Grayson, an outspoken and unpredictable liberal firebrand, is already unleashing attacks against Murphy and the Democratic establishment. (You can read more about Grayson's antics here.) With a late primary, the prospect of either a weakened nominee or Grayson as the party's standard-bearer continues to worry party officials. And regardless of the party's nominee, President Obama's actions engaging with Cuba and Iran will make the statewide political environment a little more difficult for Florida Democrats in 2016.

Finally, in North Carolina, Democrats have struggled to land a challenger against Burr. Hagan declined to run, while Democratic officials are working to get Transportation Secretary Anthony Foxx to reconsider a campaign. If neither gets in, the party's hopes would rest on a roster of lesser-known, untested candidates. Burr's stature as head of the Senate Intelligence Committee and deep war chest ($3.8 million at the end of June) make him tough to beat, especially in a state that Mitt Romney carried in 2012. Indeed, much of the state party's efforts next year will be focused on ousting vulnerable GOP Gov. Pat McCrory over taking on Burr.

Democrats need to catch some breaks in these four states to feel good about their chances of winning control of the Senate. They've been mostly successful in landing their favored candidates, but they've been forced to deal with circumstances outside their control—unexpected primary battles (Florida), candidates they can't handle (Pennsylvania), and the decision-making process of one individual (New Hampshire). Party leaders have been good at recruitment, but now they need to get a little lucky.

This article is from the archive of our partner National Journal.

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