In a sign that New Hampshire is at risk of falling off the map of Senate battleground states, the main super PAC aligned with Senate Republicans said on Friday that it was canceling $5.6 million in television ads that it had reserved in the state for the final two weeks of the race.
Once seen as one of the Republican Party’s top chances to pick up a seat in 2022, the party nominated Don Bolduc, a hard-right retired Army general, to run against Senator Maggie Hassan, a Democrat. Mr. Bolduc has sparred with state’s popular governor, Chris Sununu, a Republican who tagged Mr. Bolduc in turn as a “conspiracy-theory extremist.”
National Republicans had spent money late in the race to prevent Mr. Bolduc’s nomination but he won the primary in September anyway.
“As the cycle comes to a close, we are shifting resources to where they can be most effective to achieve our ultimate goal: winning the majority,” said Steven Law, the president of the super PAC, the Senate Leadership Fund.
A spokeswoman for Mr. Bolduc said he would continue to meet voters “one by one” in town halls, in defiance of the national group’s vote of no confidence.
“General Bolduc has defied the naysayers from the beginning and that’s the same approach he is going to take through the finish line to victory,” the spokeswoman, Kate Constantini, said in a statement.
The move by the Senate Leadership Fund comes on the heels of the National Republican Senatorial Committee canceling its television reservations in the state two weeks ago.
At the time, Chris Hartline, the communications director for the N.R.S.C., said, “We’re glad to see Republican outside forces showing up in a big way in New Hampshire, with millions in spending pledged to take down Maggie Hassan in the final stretch.”
Now those outside forces are retreating, as well.
Mr. Hartline said on Friday that “our most recent polling has the race inside the margin of error.”
“Don Bolduc is working his tail off and has turned it into a tossup,” he said. “There’s no reason to think he can’t win this race.”
The decision puzzled some Republicans. Tom Rath, a longtime Republican activist and leader in New Hampshire, wrote on Twitter of the ad cancellation: “Seems odd given recent polling showing race within the margin.”
Matt Schlapp, the chair of the American Conservative Union, called the move “odd,” as well, saying the race was “almost tied.”
Of Mr. Bolduc, Mr. Schlapp wrote on Twitter while misspelling his name, “If he does pull it out without Senate help he will become their worst nightmare. Keep your eyes on NH.”
An internal poll released by the Bolduc campaign on Thursday showed Ms. Hassan leading Mr. Bolduc 49 percent versus 47 percent with likely voters, within the margin of error.
Ms. Hassan entered October with $4.8 million. Mr. Bolduc had less than $800,000.