Sen. Kelly Ayotte, R-N.H., plunges into the dunk tank during a campaign visit to Old Home Days in Loudon, N.H., on Aug. 13. (Jim Cole/AP)

MANCHESTER, N.H. — At a rally here last week, Mike Pence showed the crowd a clip of Gov. Maggie Hassan awkwardly trying to defend Hillary Clinton’s honesty.

“Governor Hassan, let me help you out — the answer’s no,” the Republican vice-presidential nominee riffed on Hassan’s non-answer to whether Clinton was honest, drawing applause and laughs from the crowd. “And that’s why we need Kelly Ayotte back in the U.S. Senate!”

It was the perfect set piece for Ayotte — the first-term senator from New Hampshire who is fighting a tough race against Hassan (D) for reelection. Except the Republican senator wasn’t there to reap the benefits. Instead, she was across town visiting a halfway house for men overcoming opioid addiction, and accepting awards from a small-business organization and AARP.

Ayotte, in fact, is staying as far away from the campaign of Donald Trump as she possibly can, despite being in a fiercely competitive race in which she would normally be embracing whatever attention and help she could get from the top of the ticket.

Ayotte says she is going to vote for Trump but has withheld her endorsement, meaning she will not campaign with him — essentially conceding that she does not feel comfortable telling others to vote for Trump. It’s a risky position that makes her one of the only Republicans in the country who has refused to take a firm stand for or against her party’s standard-bearer.

In an interview in Amherst last week, Ayotte wouldn’t rule out shifting her position on Trump. She said she has no plans to change her vote and wouldn’t identify any single issue that could sway her, but she said she reserves the right to reconsider.

“For every person you vote for, essentially you’re always going to leave open the opportunity to reevaluate,” Ayotte said. “How could I not say that about any situation?”

The Republican incumbent said her position is genuine and the difference between voting for Trump and a true endorsement should be obvious. It isn’t as if she hasn’t endorsed a presidential candidate in the past. She was a full-fledged booster of 2012 GOP presidential nominee Mitt Romney.

“I was at every event,” she said in an interview last week. “I was there introducing him and literally going door-to-door for him. I think there’s a big difference.”

Ayotte is one of six Republican incumbents running in states President Obama won in 2012. Though she is running ahead of Trump in New Hampshire polls, Republican strategists concede that a Trump loss of significant proportions could pull incumbents such as her down with him and hand the Senate majority to Democrats. Among the most vulnerable GOP senators, Pennsylvania’s Pat Toomey has not endorsed Trump and Illinois’ Mark Kirk withdrew his early support.

Ayotte has tangled with Trump once directly, saying she was “appalled” that he would “disparage” the parents of Capt. Humayun Khan — the Muslim soldier who died facing a suicide bomber in Iraq in 2004. For that she drew Trump’s ire — he called her “weak” and said she had “zero support” in New Hampshire. He later reversed course.

The senator is betting that Republican voters will see her choice to avoid the Trump campaign as a sign of independence, representing duty to her party without the enthusiasm and vigor of embracing the campaign.

“I’m like anyone else in this country, and I get a vote,” Ayotte said.

Her decision, however, to straddle the fence could become untenable for the independent voters who make up approximately 14 percent of  New Hampshire’s electorate. Trump is lagging behind Hillary Clinton by more than eight percentage points, according to the RealClearPolitics polling average in New Hampshire — despite winning the first-in-the-nation primary in February. And some undecided conservatives think Ayotte should drop her party’s volatile presidential nominee quickly.

“I can’t vote for Trump,” said Concord resident Whit Symms. “He’s an embarrassment.”

Symms, a conservative independent, went to see Ayotte speak Thursday at a town-hall-style event in Concord. Symms said he has been impressed by Ayotte in the past and liked the way she responded to a question about how she would audit the Pentagon. But when it comes to her position on Trump, he is disappointed.

“She’s a fake,” Symms said.

Many loyal Republicans — who made up 46 percent of the state’s primary voters, according to a February survey conducted by WBUR radio — empathize with Ayotte’s hold-your-nose vote for Trump. But they aren’t the ones she needs to convince. Depending on which poll you believe, around 17 percent of New Hampshire voters may still be undecided in the Senate race.

Democrats have adopted a double-barreled attack to exploit Ayotte’s position by labeling her both an extremist and a squish.

“She is standing with Donald Trump,” Hassan said in an interview in her office Thursday.

“I think she’s just trying to distance herself from Donald Trump and mislead people on her own record,” Hassan said. “The fact that she’s willing to vote for Donald Trump and vote to put him in the Situation Room with access to nuclear codes tells you how much she puts political party ahead of anything else.”

But Trump’s large shadow over the race means that Republican attempts to exploit Clinton’s baggage — such as the question to Hassan over Clinton’s honesty — may not gain traction.

“I certainly could have answered the question better,” Hassan said. “I was really focused on listing the reasons I support her.”

Meanwhile, outside groups such as Emily’s List and former New York mayor Michael R. Bloomberg’s super PAC, Independence USA, have spent more than $10 million since June 1 attacking Ayotte. The GOP senator has a strong record of voting in favor of gun rights and is antiabortion.

The television blitz includes a new ad from Bloomberg’s group that asks, “If she’s so independent, why is she still supporting Trump?”

This isn’t the kind of campaign Ayotte hoped to be running. She acknowledges she didn’t expect to be inundated with questions about whether her party’s nominee is fit to be president — but she’s adapting.

“No matter what you’re doing, you have to deal with the conditions you’re given,” she said. “The thing about this race, though, is the fundamentals haven’t changed. … The way I’ve been getting out with New Hampshire voters is how I planned to do it.”

She is responding with an ad of her own, which she plans to release this week, that shows her grabbing a baseball bat and knocking away a string of attack ads pictured as baseballs.

There are other aspects of the race that make it very competitive regardless of the Trump factor. Both women hold statewide office and are well known to voters across the aisle. One thing working in Ayotte’s favor is that 78 percent of voters in a recent CBS News poll said they think she is a different kind of Republican than Trump.

Ayotte and Hassan have been involved in New Hampshire politics for more than a decade — Hassan was elected to the New Hampshire state Senate in 2004, the same year Ayotte became the state’s attorney general. Hassan is the only sitting governor running for U.S. Senate this year.

Hassan touts her bipartisan history of working with state lawmakers to expand Medicaid and get assistance to the state’s low-income residents and people fighting addiction.

“Bipartisanship isn’t about not having disagreements,” Hassan said. “It’s about what you do when you do [disagree].”

Hassan touts her experience leading New Hampshire through a period of economic growth. The state reported a 2.8 percent unemployment rate in June, one of the lowest in the country.

“More people are working than in any time in our state’s history,” Hassan said. “We’ve been rated the best state on over a dozen measures of economic strength, community safety and quality of life.”

For her part, Ayotte serves on a number of influential Senate committees, including Armed Forces, Commerce and Homeland Security. She was also a leading sponsor of a bill to combat opioid addiction that was signed into law last month.

But instead of debating policy, Ayotte has spent nearly all of her time responding to Trump’s near-daily controversies.

Many of her Republican supporters say they empathize with her predicament. Joe Maloy, a Republican from the Concord area, said sometimes Trump’s over-the-top comments make him wish Republicans could go back in time and “put the genie back in the bottle.” But at the end of the day, he still plans to back the GOP nominee.

“If you’re aligned with a party, you need to respect that while you may not agree with the choice, you’re a member of the party,” Maloy said. “For party leadership to be fractious, that’s not helping anybody.”

Maloy said that he understands Ayotte’s position of supporting but not endorsing Trump — and that he will aggressively back Ayotte and other down-ballot Republicans.

“Any candidate I can stand next to and believe in and respect as much as Kelly, I will stand next to them,” he said.