PORTSMOUTH, N.H. – Donald Trump’s arrival here Wednesday could not have been more dramatic had it been scripted for his television series: The black helicopter emblazoned with his name swooped out of a drizzling morning sky. He strode across the tarmac toward an airport hangar packed with reporters, the massive door rolling up slowly to reveal his presence.

Trump was even more buoyant than usual, unfazed by the fact that President Obama had released his long-form birth certificate, a document whose existence the combative developer and reality television host had questioned for weeks.

“Today I am very proud of myself because I’ve accomplished something that nobody else has been able to accomplish,” Trump declared, once he was certain all the television cameras were rolling. ” I am really honored, frankly, to have played such a big role in hopefully, hopefully, getting rid of this issue.”

Now, he said, the focus could return to the country’s pressing problems. Then, moments later, he questioned how Obama got into Harvard Law School. He also took time to plug the May 22 season finale of his NBC show “The Celebrity Apprentice,” saying that after the series concluded he would make an announcement about his plans.

“You’re going to be very surprised,” he promised.

Trump’s daylong swing through this key presidential primary state was the latest installment of his newest production: a flirtation with a White House bid that has found surprising traction.

His platform has been, like Trump, bombastic and issued with certitude if not facts: In addition to going after the president’s honesty, he has asserted that the United States should take over the oil fields in Libya and Iraq, threatened to put a 25 percent tariff on all Chinese goods and pledged to strong-arm oil-producing countries.

“It would very easy and very quick to get gasoline prices down,” Trump said, adding that Obama could do so if he “gets off the basketball court or whatever he’s doing.”

Although Trump’s antics have been mocked by much of the political establishment, he has soared to the top of recent GOP presidential primary polls, aided by the low-key approach of other would-be candidates.

Indeed, judging by the reaction at Portsmouth’s Roundabout Diner, which offered a special three-egg omelet called “The Donald” on Wednesday morning, Trump is emerging as a sort of folk hero. As the mogul’s black stretch limo pulled up outside, Brent Morrill hurried his two young daughters into the diner, telling them they were about to meet “one of the richest men in the world.”

“I’m psyched,” Morrill said about the prospect of Trump running. “He’s a good businessman, and you’ve got to be a good businessman nowadays to run the country. I think he has the brains for it.”

As Trump entered the restaurant, he was greeted with whoops and applause. “Here’s the deal: I’m not firing anybody,” Trump announced, drawing guffaws at the reference to his “Apprentice” catchphrase.

Not everyone was sold on how Trump has perpetuated false rumors about Obama’s birth: “I think it’s silly — it’s a waste of everyone’s time,” said Julie Cole, 38, who works in marketing. But she said she supported his other ideas.

“I’m not sure how electable he’ll be. But I think a lot of things that he says, especially his business sense, makes a lot of sense for the country,” Cole said.

The latest bout of Trump mania has triggered incredulity among many New Yorkers who have worked and clashed with the developer over the years.

“Donald Trump is the biggest huckster that America has ever produced,” said former New York City Mayor Ed Koch. “The issue he is running on is senseless and he knows it. I’d say even if he has the bug, he will not run, and those who now support him and the press that gave him ink will ultimately feel they were had — and once again, they were.”

Trump insisted Wednesday he was deadly serious, asserting that a recent CNN poll showed him and Obama in a statistical tie. Like his past comments about the birth certificate, that was wrong; CNN noted it had never matched the two in a poll.

“I think I have the temperament,” he told reporters. “I really do. I think what I would do is make this country rich again.”

Trump admitted that one of the biggest factors in deciding whether to run for president would be the impact on his TV career.

“I would have to give up one of the most successful shows on television, which is a lot of money and a lot of prestige and a lot of power,” Trump said as his stretch limo pulled up behind him. “You know, it’s very cool being a television star.”