TAMPA, Fla. — Mitt Romney launched his fall campaign for the White House Thursday night with a rousing, remarkably personal speech to the Republican National Convention and a prime-time TV audience, proclaiming that America needs “jobs, lots of jobs,” and promising to create 12 million of them in perilous economic times.

“Now is the time to restore the promise of America,” Romney said to a nation struggling with 8.3 percent unemployment and the slowest economic recovery in decades.

Often viewed as a distant politician, Romney made a press-the-flesh entrance into the hall, walking slowly down one of the convention aisles and shaking hands with dozens of delegates. The hall erupted in cheers when he reached the stage and waved to his cheering, chanting supporters before beginning to speak.

“I accept your nomination for president,” he said, to more cheers.

Then he pivoted into personal details of family life, recounting his youth as a Mormon, the son of parents devoted to one another, then a married man with five rambunctious sons.

He choked up at least twice, including when he recalled how he and wife Ann would awake to find “a pile of kids asleep in our room.”

He was unstinting in his criticism of President Barack Obama, his Democratic quarry in a close and uncertain race for the White House, and drew cheers when he vowed to repeal Obama’s signature health care law.

“This president can tell us it was someone else’s fault. This president can tell us that the next four years he’ll get it right. But this president cannot tell us that you are better off today than when he took office,” Romney declared.

“I will begin my presidency with a jobs tour. President Obama began his presidency with an apology tour,” he said, then accusing the incumbent of failing to support Israel while exercising patience with its arch-enemy, Iran.

In introducing Romney, Florida Sen. Marco Rubio linked his family’s immigrant story to that of omney’s, saying the shared experiences were testimony to what makes America an exceptional nation.

Rubio balanced his address to a riveted audience to include elements of his own background that have endeared him to the party with a full-throated endorsement of Romney’s capacity to lead the nation, while also zinging Obama.

Beyond the heartfelt personal testimonials and political hoopla, the evening marked one of a very few opportunities any presidential challenger is granted to appeal to millions of voters in a single night.

The two-month campaign to come includes other big moments — principally a series of one-on-one debates with Democrat Obama — in a race for the White House that has been close for months.

In excess of $500 million has been spent on campaign television commercials so far, almost all of it in the battleground states of Florida, North Carolina, Virginia, New Hampshire, Ohio, Iowa, Colorado and Nevada.