In a sign that Republicans are shifting focus to bolster Senate candidates, the conservative US Chamber of Commerce on Oct. 21 launched an ad that touted Ayotte as a hedge on the White House and suggested Hassan would be "unchecked by a new president in Washington."
In Ayotte, 48, the GOP has an advocate on national security, with a law and order background, from a competitive state. She serves on the Armed Services, Homeland Security and Budget committees, and as counsel to Majority Leader Mitch McConnell, R-Ky. Among other national issues, the first-term senator has campaigned to keep the Air Force's budget axe away from the A-10 Thunderbolt II, which her husband flew in Iraq.
Mentioned as a possible running mate for Republican presidential nominee Mitt Romney in 2012, Ayotte should continue a promising political career if she wins Nov. 8, said Nathan Gonzales, of the Rothenberg & Gonzales Political Report.
"If Sen. Ayotte hadn't been running for re-election, I think she would have been on the short list of running mates for a normal [presidential] nominee," Gonzales said. "There are a lot of attractive things there that are contrary to most of the Republican [field], but she would probably have to be reelected to keep that going."
In a Democratic-leaning state like New Hampshire, the political lifespan of any Republican senator would always be tenuous. Considered one of the Senate's "Three Amigos," with Sens. Lindsey Graham and John McCain, she is the only one who does not come from a solidly Republican state.
Fighting for her political survival, Ayotte has always been chilly toward Trump. However, Trump endorsed her, McCain and House Speaker Paul Ryan in August in a play at party unity that turned out to be short-lived. All three lawmakers subsequently rebuked Trump after a 2005 video surfaced on Oct. 7 of him having a lewd conversation that included remarks about groping women, and his campaign has fired back at all three to varying degrees.
Before she rejected him outright, Ayotte was on a Trump tightrope for months, pledging to vote for Trump as her party's nominee while refusing to endorse him and distancing herself from his statements.
During a televised debate against Hassan Oct. 1, Ayotte made an unforced error — saying she would would "absolutely" point to Donald Trump as a role model for children. She later issued a statement saying she "misspoke," and told CNN Oct. 24, "I made a mistake."
When the Trump video surfaced, Ayotte rescinded her endorsement, calling Trump "a candidate for president who brags about degrading and assaulting women." She has said she would write in Trump's running mate, Indiana Gov. Mike Pence.
"I stood up and called Donald Trump out on many occasions," Ayotte said. "That tape for me, having served as a prosecutor, was fundamentally different. That to me is why I'm not voting for him. And I'm not voting for Hillary Clinton either, because I can't support her policies."
Still, Ayotte has been under a continuous barrage from Hassan, in television ads and mailers. Ayotte has been hitting back, pollsters say, campaigning hard on her foreign-policy and national security credentials, but to limited effect.
"This isn't a foreign policy election, despite what's going on throughout the world," Smith said. "It's not gaining traction because this is more of a celebrity election. In the [presidential] debates, foreign policy comes up for a second or two before it devolves into name calling."
After the third presidential debate, in which Trump suggested he might not accept the outcome of the election, Ayotte sought to distance herself again, telling NBC News that Trump needs to "accept the outcome."
Ayotte's statement followed one from Hassan, saying, "Senator Ayotte must take responsibility for the fact that she has legitimized Trump's campaign for months by supporting him for president."
One cause for Ayotte and her backers to hope is that the latest poll may be inaccurate.
Tennessee Republican Rep. Marsha Blackburn, a Trump supporter, told CNN on Oct. 21 Ayotte has an "incredible" voter mobilization team, adding, "Kelly Ayotte is running stronger than those polls indicate."
According to Smith, the Granite State poll does skew Democratic because, as Trump's popularity dives, state Republicans have been less likely to participate in polls—a phenomenon he called a "spiral of silence."
"I think the race is probably closer than polls indicate," Smith said. "When people think the top of their ticket is unpopular or their candidate is losing, they just don't answer the phones to talk to pollsters."
Of the Republicans who did reply, 69 percent felt favorably toward Ayotte, while 78 percent of Democrats felt favorably towards Hassan, which makes them comparable. However, 81 percent of Republicans polled said they would vote for Ayotte, and 84 of Democrats said they would vote for Hassan. Independents are almost evenly split.
That means turnout will make all the difference.
"The key problem for Ayotte is to make sure Republicans will show up," Smith said, "and not just stay home because they don't like Trump at the top of the ticket."
Email: jgould@defensenews.com
Twitter: @ReporterJoe
Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.