STRATHAM, N.H. — Mitt Romney — suddenly the subject of wild speculation about a third presidential run — leveled a broad-based attack at President Obama in this first-in-the-nation primary state, while a new national poll shows more Americans wish the former Massachusetts governor, not Obama, were president now.

“We’re really at a crossroads,” Romney said. “We’ve a president … laying out a course for America that has resulted in people having a hard time finding a job. People are having a hard time making ends meet, because wages aren’t going up even as their costs are going through the roof. People are having a hard time paying the electric, gas and gasoline bills. People are having a hard time.”

Romney added, “The president and his agenda hasn’t helped. At the same time, we’ve lost a lot of esteem and influence we’ve had around the world because instead of shaping events as a nation and using our soft power … we’ve become a victim of circumstance.”

Romney also attacked Obamacare’s pending employer mandates as a job killer, and proposed carbon taxes as unfair and ineffective.

Meanwhile, a Quinnipiac University poll released yesterday found 45 percent of respondents say the country would be better off with Romney in the Oval Office, while 38 percent think we’d be worse off. It also found more Americans consider Obama the worst president since World War II.

“I can say that’s a very nice incentive if he were thinking about running,” pollster Tim Malloy, assistant director of polling at Quinnipiac University, said of Romney. “Hindsight is being very kind to Mr. Romney.”

Yet Romney continued to deny he intends to take advantage of his surge in popularity. A Suffolk University/Boston Herald poll last month also showed Romney leading the 2016 GOP presidential field by a better than 2-to-1 margin.

“No,” Romney said when asked about another White House run, as he shook hands and signed autographs following his hearty endorsement of Scott Brown’s Senate run at Scamman Farm — the same place Romney announced his 2012 presidential run.

Tim Copeland, a New Hampshire state representative who backed Romney in 2012, said he “stands a good chance” of winning if he decides on another bid.

“I’d be out campaigning for him,” said Gayle Huff, Brown’s wife, who’s been hitting the campaign trail for her husband. She added she would “absolutely” back his run, saying he “is a very good and a very dear friend of ours.”

Former Granite State Gov. John Sununu, who introduced Romney, cited the Quinnipiac poll on Obama and said, “The public is finally understanding that the emperor, the self-appointed emperor, has no clothes.”

Sununu called Romney “the man who should have been the 44th president of the United States,” while Brown referred to his political mentor as “an upright and capable man who we wish were president.”