Now, political analysts say Democrats are clinging to their chance of gaining the five seats they need to reclaim the chamber after two years amid signs that Republican candidates from New Hampshire to Nevada are still paying a price for Trump’s many controversies.

WINDHAM, N.H. — This was always going to be a tough year for Republicans to retain control of the US Senate, based simply on the numbers: They are fighting to defend 24 of the 34 seats up for grabs. But then Donald Trump burst onto the scene, sinking Republican prospects even further with his divisive rhetoric over race, immigration, religion, and gender.


Specialists who track Senate races say the latest news that the FBI is reviewing e-mails that may be related to Hillary Clinton’s use of a private server is having a marginal effect on races down the ballot — so far.

The fallout could worsen for Democrats if the presidential race continues to tighten or Trump surges into a lead in the final days before next week’s vote. Republicans are hopeful that Democrats may be hurt by the FBI’s revived interest in the e-mails as well as by the continuing release of other e-mails hacked from the Clinton campaign and released by WikiLeaks. At the very least, the news is giving Republicans plenty of fresh ammunition.

“Obviously, the odds are the Democrats will take the Senate, but I think we have to be cautious,” said Nancy Dwight, a former executive director of the National Republican Congressional Committee. “Now, with this stuff coming out of WikiLeaks, raising doubts about Clinton, it makes me wonder.”

There are signs some voters may be rethinking the choices.

New Hampshire Secretary of State William Gardner said a dozen voters who had cast absentee ballots called his office between Friday, when the FBI news broke, and Monday, asking if they could change their vote. He called such second-guessing not unusual in a primary, when candidates often drop out late, but unprecedented in a general election.


He said the voters were told they could change their votes only if they voted in the first two hours after polls open on Tuesday, before absentee ballots are processed.

If Democrats regain the Senate, it would deliver an enormous boost to Clinton — if she is able to hold off Trump in the final week — making it easier for her to fill Supreme Court vacancies and advance a legislative agenda.

Democrats need five seats to retake the Senate outright but only four if Clinton wins, because Tim Kaine, as vice president, would cast the tiebreaking vote. Forecasts show Democrats poised to win five to seven seats. In the House, the Republicans are expected to retain the majority but are poised to cede 10 to 15 seats, well short of the 30 Democrats need.

“Republicans basically poured kerosene on a tough map by nominating Donald Trump,” said Doug Heye, a Republican strategist and former spokesman for the Republican National Committee. “There is a palpable sense among Republicans that had we nominated anyone else, we would be in much better shape. Senate candidates would not be in a position to have to outperform the Republican nominee.”

Making matters more difficult for the GOP, several candidates have made awkward attempts to distance themselves from their unpopular nominee.

In New Hampshire, Senator Kelly Ayotte initially said she would vote for, but not “endorse,” Trump. Then she said she misspoke when she suggested during a debate that Trump was a role model for children. Finally, after the release of the video that showed Trump bragging about groping women, Ayotte renounced her support entirely, triggering a fresh round of criticism from her Democratic challenger, Governor Maggie Hassan.


“I just think the way she approached Donald Trump really reflects the way she’s approached her job, and shows a remarkable lack of judgment,” Hassan said.

Ayotte, speaking last Friday in Windham, avoided any mention of the man running for the White House. She seized on the latest FBI’s latest review of e-mails from Clinton’s aides, saying in a statement that Hassan “needs to answer for her inability to call [Clinton] out, even on her most egregious national security failures.”

In Nevada, Joe Heck, a Republican congressman running to replace Senate minority leader Harry Reid, drew boos at a rally outside Las Vegas last month when he called upon Trump to withdraw from the race after the “Access Hollywood” video surfaced.

Heck later said at a closed-door fund-raiser that Republicans had cut Trump “a lot of slack” for months, according to CNN, which obtained a recording of Heck’s remarks.

“I want to support him, I really do,” Heck said in the audio, but his “worst fear” is that Trump will depress Republican turnout on Tuesday. Heck holds a slight lead over Democrat Catherine Cortez Masto, a former state attorney general whom Reid has endorsed.


Trump’s lack of support among white, college-educated women in suburban Philadelphia could hurt Senator Pat Toomey, a Pennsylvania Republican who is battling against Katie McGinty, a former state and federal environmental official.

In his closing ad of the campaign, released Monday, Toomey tells voters: “I have a lot of disagreements with Donald Trump — and I’ve been very clear about that.” Still, he has refused to say if he will vote for Trump on Tuesday.

In North Carolina, one Republican county headquarters has decided to ignore Trump entirely and focus on reelecting Senator Richard Burr and other down-ballot Republicans, said Heye, who visited recently.

“There were no Trump signs anywhere,” he said.

Polls show Democrats are also waging close races in Missouri and Indiana, and have pulled ahead in Illinois and Wisconsin.

“If anybody other than Trump were the nominee, everything would be reversed,” said Rich Galen, a former aide to Newt Gingrich and Dan Quayle. “This would be a walkover. The Democrats would be running in terror. But I think Trump is a huge drag on the ticket and the best Republican candidates can hope for is that, even if he doesn’t win a state,” he keeps the margin close enough to give Senate candidates a shot at victory.

Several Republican senators, such as Ohio’s Rob Portman, Arizona’s John McCain, and Iowa’s Chuck Grassley, are running well ahead of Trump in their states by successfully making a “distinction between the Trump brand and the Republican brand,” said Whit Ayres, a GOP pollster and strategist. But it remains a difficult dance for party incumbents, he said.


“It’s strategically challenging because they have to have almost all the Trump voters plus a share of the Clinton voters,” Ayres said.

While Democrats express optimism about their Senate prospects, they will be fighting uphill during the midterm election in 2018. That year, Democrats will have to defend 25 of the 33 Senate seats in play.

“In 2018, it’s a totally different ballgame,” said Jennifer Duffy, senior editor of the Cook Political Report. “Republicans will have every advantage.”

The 2016 election

Michael Levenson can be reached at mlevenson@globe.com. Follow him on Twitter @mlevenson. Tracy Jan can be reached at tracy.jan@globe.com. Follow her on Twitter @TracyJan.