Ward Baker has a tough act to follow: his own. As the National Republican Senatorial Committee’s political director during the last election cycle, the former Marine helped orchestrate a stunning nine-seat GOP gain, seizing Senate control for the first time since 2006.

Baker’s reward was a promotion to executive director — and a 2016 map so unfavorable to his party that the Democratic path back to control of the Senate need not veer outside states that Barack Obama carried twice in his presidential elections.

Baker is well aware of the challenge of playing mostly defense, with more than twice as many Republicans up for re-election next year as there were in 2014. Democrats faced a similar hurdle last year and were pummeled. Sitting in his office, Baker jumps out of his seat to point out a quote taped to his door from his counterpart at the Democratic Senatorial Campaign Committee, who, in March predicted “a very Democratic Senate” in the next Congress.

“I don’t know what they’re going to do over there [at the DSCC],” he says, “but I can promise you this: I hope they are ready for a fight, because we are going to bring it to them.”

This time around, the initial conditions appear ideal for Democrats: defending just two competitive seats (Nevada and Colorado), strong offensive opportunities in six states that Obama won twice and presidential-level voter turnout, which tends to benefit Democrats.

“I continue to feel excited about the map,” says DSCC Executive Director Tom Lopach. “When we got here we knew it wasn’t going to be easy, but we knew it was a damn good map and a good year.”

At the same time, as helpful as the map is for Democrats, it’s not as bountiful as the one Republicans profited from last cycle.

Based on 2012 presidential results, the GOP’s advantage was far greater when comparing its top six pickup opportunities in 2014 (Alaska, Arkansas, Louisiana, Montana, South Dakota and West Virginia, all of which Republicans won) with the top six for Democrats next year (Florida, Illinois, New Hampshire, Ohio, Pennsylvania and Wisconsin). In the last presidential election, Mitt Romney carried the six top GOP targets in 2014 by an average of 19 points, while Obama in 2012 carried the six top Democratic targets in 2016 by an average of just 6 points, with a 17-point victory in his home state of Illinois a notable outlier.

For Republicans, the aim is clear: Keep Democrats from netting more than three seats next year. A five-seat gain would give Democrats 51 seats, but the party could also control the chamber by picking up four seats and retaining the White House, giving the vice president the tiebreaking vote.

In the War Room

The NRSC has put itself — quite literally — on a war footing to defend the Senate. The group holds its political strategy meetings in a conference room adorned with sandbags, fake barbed wire and camouflage netting blanketing the ceiling. It’s also doubling down on training, not only among candidates but also the staff running their campaigns.

Fifteen campaign managers, all but one working for an incumbent, attended a four-day seminar at the NRSC in July. They sat through about a dozen classes with specialists on data, technology, media, polling, vote goals and field programs, with representatives from companies including Periscope and Pandora presenting about the political opportunities with their products.

Before the success of 2014, Republican attempts at securing the majority had been tripped up by ultraconservative or gaffe-prone nominees whose mistakes, in some cases — Missouri’s Todd Akin, for one — hurt fellow GOP candidates in races across the country. After the 2012 and 2014 elections, Baker and others at the NRSC interviewed campaign operatives and candidates from the past several cycles in search of what the committee could do to improve the party’s hand.

“The bad candidates, everyone thinks the solution is working with the candidate,” says Deputy Executive Director Kevin McLaughlin, who ran a training program for press secretaries as an NRSC senior adviser last cycle. “But a lot of times we had underqualified staff putting their candidates in bad situations or responding poorly or not prepping them right. Whatever it might be, there’s a two-pronged problem here: It all rests on the candidate’s shoulders, but the staff has to be up to speed as well.”

Running in a presidential year is also inherently different from a midterm, when voters can best express their unhappiness with the current occupant of the White House by voting against his party in a congressional race. Next year, every Senate campaign, particularly those in presidential swing states, will be waged beneath a mountain of media attention and ad spending focused on the next commander in chief.

There is also a trend away from split-ticket voting, which places a heightened importance on the electability of the two presidential nominees. With the Republican nomination fight a tossup, and with Vermont Sen. Bernard Sanders challenging Hillary Rodham Clinton on the Democratic side, it’s enough to keep Senate strategists up at night.

It’s most troubling for Republican incumbents such as Mark S. Kirk of Illinois, Patrick J. Toomey of Pennsylvania and Ron Johnson of Wisconsin, who represent states likely to be carried by the next Democratic nominee, no matter who it is. The fortunes of those GOP incumbents, along with New Hampshire’s Kelly Ayotte, Ohio’s Rob Portman and Rep. Joe Heck — who’s vying for the GOP’s top pickup opportunity, the open seat in Nevada — will hinge on a significant number of voters choosing both them and the Democratic nominee.

“We worked closely with the RNC to improve our ground game in our target states, but that was last year and it’s a whole different universe now,” Baker says.

Democrats would face the same issue if they are serious about being competitive in states more favorable to Republicans, such as Indiana and Missouri. In an effort to expand the Senate map as much as possible, Lopach says to expect to see more Democratic announcements from “uniquely capable candidates in places folks didn’t expect us to be playing.”

Beyond New Hampshire, where Democratic Gov. Maggie Hassan is still deciding whether to challenge Ayotte, and North Carolina, where recruitment against GOP Sen. Richard M. Burr continues, Lopach mentioned Arkansas, Georgia and Kentucky — all of which the party lost by significant margins last year — as potential opportunities.

“I feel good about our recruiting,” he says, “and if I were [the NRSC] I’d be a little nervous.”

Republicans have a few primaries to watch for in the open seats in Indiana and Florida, but, unlike in previous years, Democrats have several of their own.

The DSCC hopes Rep. Tammy Duckworth emerges unscathed from the Illinois primary against former Chicago Urban League CEO Andrea Zopp in the party’s top pickup opportunity. Its nominee in Pennsylvania will be either former Rep. Joe Sestak, who lost to Toomey in 2010, or Katie McGinty, a Clinton administration alumna and unsuccessful candidate for the Democratic gubernatorial nomination in 2014.

There are multiple wrinkles in Florida. Two Republican presidential contenders hail from the state, and as the nominee, either former Gov. Jeb Bush or outgoing Sen. Marco Rubio could offer down-ballot coattails in the general. There’s also a court-ordered, mid-decade redraw of the congressional map underway, prompting four House members to vie instead for the two Senate nominations. The Democrats are Patrick Murphy, who was endorsed by the DSCC, and Alan Grayson, who is personally wealthy, liberal and prone to unfiltered outbursts. The GOP House members are David Jolly and Ron DeSantis.

For Democrats, primaries come with the new minority territory and with a map defined by the Republican wave of 2010. With even a small wind at their backs a year from now, there could well be more than enough opportunities to regain control of the chamber. From this vantage point, though, the majority is a tossup.

“We’ve lost this map twice; 2010 and 2004 were not good to us with this map,” Lopach says. “So there’s nowhere to go but up with these races.”