TAMPA, FLA. - A resurgent GOP determined to reclaim the White House nominated Mitt Romney for president on Thursday and reintroduced millions of Americans to the man who shoulders their hopes for defeating President Obama.

"Now is the moment when we can stand up and say, 'I'm an American. I make my destiny. And we deserve better! My children deserve better! My family deserves better! My country deserves better,'" Romney said to roaring applause.

Romney, who has spent a year methodically dispensing with rivals and grooming himself for this run, faces an enormous challenge in unifying a party uneasy about his conservative bona fides. But he appeared to make inroads on Thursday night, including among the divided Minnesota delegation.

"He's come alive," said Janet Beihoffer, a Republican Party committeewoman from Lakeville. "He's speaking from the heart ... He's finally letting it out. It's the best thing that's happened to us in a long time."

Amid a sea of Romney shirts and signs, the nominee said the cure for America's economic ills "is jobs, lots of jobs" and pledged to create 12 million of them. "Now is the time to restore the promise of America," he said.

Romney steered clear of sharp attacks on the president, but he said that under Obama, "promises gave way to disappointment and division."

Romney, 65, used the night to enshrine his personal narrative in front of his largest audience ever, showcasing his history as a successful business executive, loving family man, the savior of the 2002 Winter Olympics and a leader who governed Massachusetts by conservative principles.

The speech served as the high point of meticulous preparations to reintroduce Romney to Americans after his failed presidential run four years ago. His campaign has been preparing to fight back against a Democratic portrait of Romney as an uncaring multimillionaire who molds his ideology to catch the political winds of the moment.

Over three days, the convention carefully erected a theme that Romney possesses a unique mix of skills and leadership that can guide the economy back to full strength and "return America to greatness."

"When the obstacles seemed insurmountable and others panicked, Mitt was the calm in the storm," said Bob White, who has partnered with Romney on several business ventures.

Obama's campaign has pounded Romney for refusing to release specifics about his economic proposals, saying that the candidate is shielding voters from his plan to give deep tax breaks for businesses and the rich and to pay for them with deep cuts to programs that benefit the low-income and middle classes.

The night brought one unscripted moment when legendary tough guy Clint Eastwood emerged as a surprise speaker to endorse Romney. "Now might be time for someone else to come along and solve the problem," said Eastwood, who gave a rambling speech that included a prolonged "conversation" with an invisible Obama in an empty chair.

"When someone does not do the job, you have got to let them go," Eastwood said.

Romney got some of his loudest applause when he pledged greater development of American energy sources and to "repeal and replace" Obama's health care overhaul.

As a candidate who shifted his position on abortion and enacted a controversial universal health care initiative in Massachusetts, Romney has seldom been a top pick of diehard fiscal or religious conservatives. To appease the tempestuous, small-government wing of the GOP, he selected Wisconsin Rep. Paul Ryan as his running mate. The relatively young and charismatic Ryan is the architect of a budget proposal that calls for deep reductions and that has become a cherished government blueprint for fiscal conservatives.

Several Minnesota delegates found Romney's speech to be a breakthrough highlight for a man not known for high-octane deliveries. "Mitt Romney did an excellent job," said Steve Perkins, an Electoral College elector from Luverne. "He really focused on the thing. The number one issue is jobs."

While an emboldened Republican Party has coalesced around Romney, he faced one of his toughest audiences in the Minnesota delegation, which handed 33 of its 40 votes for the nomination to libertarian Rep. Ron Paul of Texas.

Hours before Romney spoke, several hundred Paul delegates from around the nation gathered in an angry rally outside the Tampa Bay Times Forum to protest new party rules that they fear will diminish their importance in future primaries and caucuses.

"We're trying to warn Mitt Romney that he's in danger of losing the election if he loses the grassroots," said Craig Westover, a Paul delegate from Minnesota.

But if Paul's followers were prepared to hold out, the Tea Partiers in the delegation seemed ready to fall in line.

"Our thing during the primary election was to find candidates who think exactly like us," said Charlie Strickland Jr., a City Council member in Ogilvie, Minn., who belongs to the Tea Party Express. "Now, we only have but two choices."