EXETER, N.H. — People often say candidate debates don't make much difference in presidential campaigns. Don't tell that to Amy Klobuchar. The Minnesota senator's performance on Friday night was like a switch being flipped for her campaign.

Sen. Bernie Sanders (I-Vt.), who won the primary here four years ago with 60 percent of the vote, remains the person to beat in Tuesday’s New Hampshire primary. Former South Bend, Ind., mayor Pete Buttigieg, on the strength of his delegate victory in the flawed Iowa caucuses, came into the state as the hot candidate hoping to overtake Sanders.

But Klobuchar now appears to be an unexpected and unpredictable force in the closing hours of the primary campaign here. She is drawing the biggest crowds of her campaign, and polls show her on the rise, potentially complicating things not only for Buttigieg, but also for former vice president Joe Biden and for Sen. Elizabeth Warren of Massachusetts.

Klobuchar is trying to maximize her newfound attention. She added extra stops to her schedule Sunday, and at the last minute, she threw on a late-night get-out-the-vote event for Monday in Manchester at a venue down the street from where President Trump was holding his pre-primary mega-rally.

On Sunday morning, Klobuchar did a quick stop at Tucker’s, a popular diner in Concord, where she found patrons at the booths and tables warming to her candidacy. Asked by reporters whether she could feel a difference since the Friday debate, she offered a big smile.

“There’s a bunch of people coming out, committing, that had been supporting other candidates,” she said. “It’s all over the place. It’s really strange. I wish I had videos of it.”

On Monday afternoon, Klobuchar filled the town hall in Exeter to overflowing. She spoke on the anniversary of her announcement speech, which she delivered in a Minnesota snowstorm. On the eve of the primary here, she appealed to her audience to get to work in the last hours and help her to “surprise the country” Tuesday.

She excoriated Trump, but she is, in the tradition of her home state, a happy warrior. Her speech was part serious policy — heavy on health care, education and economics — and part standup comedy. Interrupted by someone in the audience at one point, she hesitated and then, with a laugh, called on those in an overflow room one floor above for help. They responded by stomping their feet in solidarity, bringing laughter to the main floor audience and the candidate.

Voters in New Hampshire are still getting to know Klobuchar, who spent most of her time in Iowa before the caucuses trying to leverage her next-door-neighbor status into a significant finish. In the end, she came in fifth, which under ordinary circumstances would sink most candidates.

But this is not an ordinary year. Because the Democratic race is so unsettled, no candidate, almost no matter how badly they finish in the first few contests, will conclude that it’s time to quit, unless they’re flat out of money. And perhaps even that won’t stop them for a few weeks.

Klobuchar is lucky in another way. No other candidate has worried much about her or seen her as a threat — at least until now. She has been able to go on offense in the debates without getting much pushback in return. As Sanders, Buttigieg and Biden squared off against one another Friday night and since, nobody is spending time or money attacking Klobuchar. That could change, depending on what happens here Tuesday. For now, she has a free ride.

Klobuchar’s sudden rise comes at the possible expense of Biden and Warren. Biden’s team continues to frame his strategy around all of the first four contests, trying to play down possible disappointment in New Hampshire after disappointment in Iowa. Using a World Series analogy, Kate Bedingfield, Biden’s deputy campaign manager, told reporters at a Bloomberg News breakfast Monday, “This is game two and we’re going all the way to game seven.”

A year ago, Warren was expected to be battling Sanders for supremacy among liberal voters here in a kind of near-home-state duel. But Warren’s third-place finish in Iowa and a less-than-dominating performance at Friday’s debate at Saint Anselm College have given Klobuchar some unanticipated operating room.

None of this is to say that Klobuchar will truly be successful when the votes are counted here Tuesday night. The polls show that she is competitive with Warren and Biden but not necessarily assured of finishing ahead of them, unless she is on an unbreakable trajectory. Her future depends both on the order of finish and how close she ends up to the leaders.

The most significant potential effect of Klobuchar doing well here is to further clog up the competition to become a moderate alternative to Sanders. That was to be Biden’s calling card before Iowa happened — or more accurately, perhaps, it was Sanders who was intending to become the liberal alternative to Biden.

Buttigieg upset those Biden plans, and coming out of Iowa, he looked to consolidate his position ahead of the former vice president. That is still possible if he can power through the primary here in another head-to-head finish with Sanders. But it’s also the case that he will have other moderates to worry about heading to Nevada and South Carolina later in the month.

Klobuchar has limited resources and limited options, other than to try to maximize the moment. Just where she might strike, if New Hampshire voters give her a real push forward, is a big question. She has not proved that she can attract votes from African Americans or Latinos, who play bigger roles by far in the next two contests.

She said she has raised more than $3 million since the debate, but that’s a tiny fraction of what a candidate needs for Super Tuesday. She will be living on press coverage, every available media interview she can muster and more good debates.

The other possibility is that a solid finish for Klobuchar in New Hampshire opens the door wider for Mike Bloomberg, the billionaire and former New York mayor. Bloomberg is skipping the first four contests, a strategy never successfully employed but one that, for now, looks better than the skeptics were claiming.

Klobuchar has waged a mostly lonely campaign since her announcement a year ago, overshadowed by other candidates and overlooked by the media. In an instant, that has changed here in New Hampshire. Her moment has arrived, and she is ebullient at the opportunity. She awaits the verdict of voters in a state that can both surprise and disappoint.