“If it wasn’t already, it sure came into play last Thursday,” said Jon McHenry, a national GOP pollster who grew up in New Hampshire, referring to the first general-election debate between Biden and Trump.

Republican “reach states,” including New Hampshire, “became more competitive after that performance,” McHenry said. A year ago, the state “absolutely” looked less competitive for Republicans, he said, “whereas now, you go, ‘Hey, that’s on the table.’”

The fresh attention on New Hampshire comes as both campaigns seek to expand the map of key battleground states beyond the six that proved decisive in 2020. Immediately after last week’s debate, for example, Biden campaigned in North Carolina, while Trump traveled to Virginia, each candidate wooing a state he lost four years ago.

New Hampshire has long been a purple state; it currently has an-all Democratic congressional delegation, a Republican governor, and an almost even party split in its state House of Representatives. But not since George W. Bush in 2000 has the state backed a Republican for president — a streak that gives Democrats hope, even as Biden shows increasing signs of weakness.

“We are confident Granite Staters will come together this November to reelect President Biden and reject Donald Trump, just as we did in 2016 and 2020,” said Marisa Nahem, a spokesperson for the Biden campaign in New Hampshire.

Biden carried New Hampshire by seven percentage points in 2020, but his campaign still considers it a battleground state this time around. In 2016, when Hillary Clinton carried New Hampshire, the margin was far closer; she bested Trump by less than one percentage point.

This year’s election could more closely resemble 2016 than 2020, analysts said. And while New Hampshire is just one small state, its competitiveness forewarns of far larger consequences for Democrats.

“If New Hampshire is in play, then Donald Trump is going to win” the general election, predicted Fergus Cullen, a former New Hampshire GOP chair who opposes Trump. If Trump manages to even compete in New Hampshire, he reasoned, the former president will carry the bigger swing states with more electoral votes.

“All that’s happened in the last six months is Trump’s path has expanded and Biden’s path to winning has become more and more narrow, much more threading the needle,” Cullen added. “He’s clearly been on defense in states that should be solidly in the Democratic column. The trends are all moving in one direction.”

As national Democrats openly discuss the possibility of replacing the president on the ticket this fall, some Biden backers in New Hampshire have been quick to tamp down on such speculation. And supporters dismiss the recent poll showing Trump ahead of Biden, noting that the survey has been proven wrong before and months of campaigning remain before Election Day.

Sure, New Hampshire looks competitive — but that’s nothing new this year, said Kathy Sullivan, the former state Democratic chair who led this year’s write-in effort for Biden in the primary. Biden snubbed New Hampshire by skipping its Jan. 23 primary this year, as national Democrats sought to shift the early contests to states with more diverse populations. But he decisively won the primary as a write-in candidate despite not formally campaigning in the state himself.

Biden has made two trips to New Hampshire since he skipped the primary, attempting to reset his relationship with the state. His campaign and local Democrats have 14 coordinated campaign offices.

Sullivan said Republicans are “getting ahead of themselves” in arguing that Biden’s debate performance will sink him in the state. Sullivan said based on conversations she’s had with canvassers promoting Biden door to door with New Hampshire voters, she is not convinced that the race has tightened since the debate.

“I feel nervous about every election,” Sullivan said. “Fingers crossed, say a Hail Mary, or whatever prayer you might say, or meditate. It’s just going to be like every other election.”

Despite Republican bluster about recapturing the state in a presidential election, Trump has not campaigned in New Hampshire since he won its first-in-the-nation primary in January. A surrogate, his onetime GOP primary rival North Dakota Governor Doug Burgum, spoke at a fund-raising dinner in Keene in April.

Republican National Committee Chairman Michael Whatley told reporters in Arizona this week that as the Trump campaign worked to expand the map of battleground states, “we’ve now started to engage in Minnesota and in Virginia and in New Hampshire.”

But the RNC would not say what that effort entails. Trump campaign senior advisor and RNC chief of staff Chris LaCivita said in a statement that he did not feel “obligated … to discuss the specifics of our strategy, timing and tactics with members of the news media.” But New Hampshire GOP Chairman Chris Ager told the Globe that last month, even before the June 27 debate, the Trump campaign made a “substantial” contribution to the state party to help Republicans on the ground boost the former president’s campaign.

“It’s an indicator when the campaign starts giving money directly to the state party,” Ager said. “It’s a good sign for us that yes, we are a battleground state.”

Ager declined to say how much the Trump campaign had provided, but called it a “significant investment” — the first large chunk of money the party has received directly, and he is expecting more to come.

Before the debate, Ager said he knew New Hampshire would be close, but he wasn’t sure Trump could win it. Now, he said, he is “convinced.”

“I’m usually pretty cautious,” Ager said, “and now I’m like, ‘Oh boy.’”

Emma Platoff can be reached at emma.platoff@globe.com. Follow her @emmaplatoff.