By Steve Holland

MANCHESTER, New Hampshire (Reuters) - Republican Mitt Romney offered the starkest choice yet between himself and President Barack Obama on Tuesday in a New Hampshire primary victory speech that aides said set the tone for the rest of the campaign.

Romney gave perhaps the most dynamic speech of his campaign for the Republican presidential nomination, focusing almost exclusively on the economic record of Obama, the Democrat he wants to unseat from the White House in the November 6 election.

"We know that the future of this country is better than 8 or 9 percent unemployment. It is better than $15 trillion in debt. It is better than the misguided policies and broken promises of the last three years - and the failed leadership of one man," he said.

The strategy behind the speech, aides said, was both to offer a different vision than Obama's and to answer Republican voters' demands for a nominee who can take the fight to the president.

"When Barack Obama came to New Hampshire four years ago ... he promised to bring people together, he promised to change the broken system in Washington, he promised to improve our nation. Those were the days of lofty promises made by a hopeful candidate. Today, we're faced with the disappointing record of a failed president," Romney said.

It had the texture of a speech that Romney, as the nominee, might give during the general election campaign against Obama next autumn, even though Republicans in only two states have made their choices known thus far in the early days of 2012.

'RUN OUT OF IDEAS'

"The president has run out of ideas. Now, he's running out of excuses," said Romney. "And tonight, we are asking the good people of South Carolina to join the citizens of New Hampshire and make 2012 the year he runs out of time."

South Carolina's January 21 primary is the next contest in the Republican nomination race.

Whether Romney will be able to stay on message like he did on Tuesday is a big question.

His final day of campaigning on Monday was noteworthy for a self-inflicted wound in which he declared "I like being able to fire people" in talking about the need for competition between health insurance companies.

It played into a narrative put out by his Republican rivals that Romney was a job cutter during his time as a venture capitalist in the 1990s.

And Romney found himself on the defensive for saying he once feared getting fired from his former firm Bain Capital, where he

made his fortune.

"He leaves here wounded by a series of episodes that made it clear to voters - both in New Hampshire and for those watching across the country - that he is completely out of touch with the concerns of America's working and middle-class families," said Democratic National Committee chairwoman Debbie Wasserman-Schultz.

Romney aides were jubilant at Tuesday's results in a state where he lost four years ago to eventual Republican nominee John McCain. But they held back from declaring that the former Massachusetts governor appears to be on the path to the Republican presidential nomination.

They said Romney faces a tougher environment in South Carolina to outduel rivals who are gunning to be his conservative alternative in a conservative state where politics can get nasty.

Romney is to travel on Wednesday to South Carolina. He leads polls there but an outside group that wants Newt Gingrich to win is launching $3.4 million of ad buys in the state.

Gingrich's campaign in the past week has centered around tearing down Romney to avenge negative attacks from Romney forces against Gingrich in Iowa.

Conservatives Rick Santorum and Rick Perry want to make a stand in South Carolina as well.

"It'll be a tough, hard-fought battle in South Carolina because it's always a hard-fought battle in South Carolina," said Romney adviser Ron Kaufman, who said the New Hampshire victory should end the debate over whether Romney is a "weak front-runner" after his narrow Iowa win.

Another Romney adviser, former eBay CEO Meg Whitman, said Romney is geared toward a long campaign to win the nomination.

"Mitt's prepared to go the distance and his whole team is. so I think that's what we're planning on right now. If it ends earlier, great," she said.

(Reporting By Steve Holland; Editing by Will Dunham)