Democrats are poised to gain seats in the House of Representatives this year, but with well over a dozen competitive races still viewed as tossups just one week before Election Day, the extent of that gain -- and whether Republicans can stem the bleeding and keep a strong grip on their majority -- remains uncertain.

Democrats for months have hoped to nationalize races, tying Republicans down the ballot to Donald Trump and hoping a big loss by Trump could flip a significant number of seats. They saw gains early in October when Republican polling in swing districts fell after the release of the “Access Hollywood” recording in which Trump boasted about making unwanted sexual advances on women -- something that prompted more than a dozen Republicans to withdraw their support for the party’s nominee.

But GOP insiders say their polling in swing districts has stabilized, and they feel energized by the news Friday that the FBI is looking into emails that could be related to its previously close investigation of Hillary Clinton’s private server. Democrats have expressed outrage at FBI Director James Comey for releasing the limited and vague information about the probe, and even some Republicans have suggested it was improper to do so. But Republicans say it’s given them an opportunity to play offense during the final week in the campaign.

Democrats need to gain 30 seats to win back the majority, an extremely tall order considering there are barely more than 30 competitive districts currently in GOP hands. They hope to gain momentum in the remaining days of the campaign with strong turnout efforts that could boost their chances, while Republicans think there is new momentum on their side and believe GOP voters showing up to support down-ballot candidates could keep their losses in the single digits.

“The cake may be baked in 2016,” said David Wasserman, who analyzes House races for the nonpartisan Cook Political Report. His official prediction is a net gain of between 10 and 20 seats for Democrats, but he said that a single-digit increase is likelier than one of more than 20 seats.

“My guess is that if it falls outside that outlook ... it would be a little bit on the lower end because of increased Republican enthusiasm of the last week has a chance to save a handful of seats,” Wasserman said.

Democrats, however, argue that the map is rosier now than it was several months ago. Zac McCrary, a pollster who has worked with the Democratic Congressional Campaign Committee, said several months ago that single-digit gains appeared possible. Now he says his party’s prospects are “brighter today than they have been at any other point in this cycle.”

Democrats emphasize races like California’s 49th District, represented by Rep. Darrell Issa, or Florida’s 7th District, represented by Rep. John Mica, as evidence they’re on offense. Issa’s district has become more competitive based on demographics and anti-Trump fervor, and Mica represents a major part of the Orlando suburbs, where many voters are turned off by Trump.

The two top groups spending money for Democrats -- the DCCC and House Majority PAC -- are running ads in more than 30 districts and are hoping that a wave of support over the next week swings most of the tossup states into their column.

“I think in part the environment we’re in right now, cutting Republicans’ 30-seat majority down is always going to be a win for us and we’re going to be happy if we can significantly reduce their margin,” said Alixandria Lapp, the executive director of House Majority PAC. “Getting into double digits is certainly possible and likely, and right now we’re keeping our nose down and focusing on winning every last seat we can with the resources available to us.”

But many of the races Democrats are competing in remain tossups, and Republicans feel confident in districts that Democrats had hoped to put away weeks ago, like Florida’s 26th, where freshman Rep. Carlos Curbelo -- one of the earliest anti-Trump Republican members -- has remained competitive in a Hispanic-leaning area that will likely favor Clinton, or in Illinois’ 10th, where GOP Rep. Robert Dold -- another early anti-Trump member -- is facing a rematch against former Rep. Brad Schneider. Republican incumbents have also polled well ahead of Trump in districts in New York that appeared to be more competitive.

“I think we feel confident that the map is in a position of more stability than it was a few weeks ago, and certainly the headlines in the last few days are a shot in the arm for focusing on what the election is about,” said Emily Davis, spokeswoman for Congressional Leadership Fund, a super PAC dedicated to House GOP candidates.

One major concern for Republicans, however, is turnout. If GOP voters put off by Trump don’t show up to the polls, it could be detrimental to some congressional candidates. Even as the nominee has tightened the race with the focus turning back to Clinton and her emails, there are still questions about whether voters will show up in high numbers. In particular, Democrats are hopeful that if Clinton wins several East Coast swing states and the election is called early on Nov. 8, it could dissuade some West Coast Republicans in swing districts in California or Nevada from going to the polls late in the day.

“That’s a huge concern,” said one Republican strategist who requested anonymity to speak frankly. “If folks in New York are calling the race at 8:30, that’s going to suppress votes in California, Colorado, Nevada.”

Republicans, however, have been working hard for months to mitigate those concerns. Congressional Leadership Fund for the first time paid for ground operations in California, Minnesota and New York -- three states that aren’t presidential battlegrounds but have nearly a dozen competitive House races -- to make sure GOP turnout is high. Speaker Paul Ryan, who has feuded with Trump and is no longer defending him, still remains one of the party’s best fundraisers and surrogates. Ryan appeared at 14 events in eight cities in California last week for two GOP challengers and three incumbents. He also campaigned in two swing districts in Nevada, one in Colorado, and even in the at-large district in Montana, which Republicans believe is safe but could potentially fall if a massive Democratic wave surfaces.

Ryan plans similar events for a number of representatives in tough races over the final week of the campaign. Meanwhile, his Democratic counterpart, Minority Leader Nancy Pelosi, will be stumping with candidates in Pennsylvania and New Hampshire and raising money for Democrats across the country during the remaining days.

Overall, neither Democrats nor Republicans expect a massive shift in the House picture as the campaign comes down the stretch. Republican strategists were pleased their candidates could go on offense, talking about Clinton’s emails and arguing for a “check and balance” on a potential Clinton presidency. Democrats, on the other hand, were skeptical that the news about Clinton and the FBI would sway any previously undecided voters, and thought it could even gin up more enthusiasm among a sleepy Democratic base that some might have felt complacent.

“I’ve been a little concerned about Democrats being motivated over the last couple weeks after the last debate, and people basically writing off the race,” said Achim Bergmann, a former DCCC staffer who currently advises several House candidates. “It doesn’t help us in a lot of places. If there’s a little more energy around the race, maybe that’s good. But I don’t know that this necessarily changes that.”

Most strategists in both parties agree that in the current landscape, the House majority is not seriously in play. Democrats hope massive turnout on their side, plus a big loss for Trump and depressed GOP turnout, could change that. Republicans, however, hope that Trump continues to close the margin, and GOP voters are motivated by animus toward Clinton and belief that a Republican Congress would be important. Whether the results flow one way or the other over the following seven days will determine whether Democrats expand their margins and put the House in play in 2018, or whether Republicans are able to come away salvaging much of their majority.

“Is it possible? Yes. Is it likely? Not really,” Mark Mellman, a Democratic pollster, said of his party coming close to the majority. “It will take a pretty significant thing to change the race. But we’ve had pretty significant things a number of times in this election so far."