PORTSMOUTH, N.H. -- Their conventions behind them, President Barack Obama and Republican challenger Mitt Romney bore down Friday on the drive to November, trading barbs from key swing states on a day when a disappointing new jobs report underscored the economic anxiety that punctuates the election.

Obama dashed from the Democratic National Convention in Charlotte, N.C., to New Hampshire and then Iowa, looking to build enthusiasm in key states with first lady Michelle Obama at his side along with Vice President Joe Biden and his wife, Jill.

“Now that both sides have made their argument, there’s a big choice to make,” Obama told an estimated 6,000 people at the Strawbery Banke Museum

Romney returned to the campaign trail after a weeklong hiatus during Obama’s convention, rallying supporters in Orange City, Iowa, before heading to New Hampshire later in the day. He urged voters to see Obama’s convention speech the day before as a litany of promises unlikely to be fulfilled.

“It was a whole series of new promises that he also won’t be able to keep,” Romney said. “We would have four more years of the last four years, and the American people are going to say no to that.”

The two rivals grappled as a report Friday showed that the struggling economy added just 96,000 jobs in August. Worse, it showed that 368,000 people had stopped looking for work, sending the share of the workforce either working or actively looking for jobs to its lowest level since September 1981.

Obama acknowledged that although U.S. businesses added jobs for the 30th month in a row, “that’s not good enough.”

“We need to create more jobs, faster,” he said, then blamed Republicans for blocking his proposed package of new spending, a proposal his administration says would create one million jobs.

His vision, he said, is of an America that invests in education, research and development and believes in “the idea that we have some obligations to each other and that when we work together we all do better.” Republicans, he said, want to eliminate regulations, cut taxes for the wealthiest and believe that government, “because it can’t do everything, somehow should almost do nothing.”

Obama argued that it’s his opponents who have no new ideas, charging that the Republican solution to every problem is a tax cut.

“Tax cuts when times are good, tax cuts when times are bad,” Obama said. “Tax cuts to help you lose a few extra pounds, tax cuts to improve your love life. It’ll cure anything, according to them.”

He contended he backs tax cuts and has signed them “for people who need it,” but opposes them for the wealthiest.

“I do not believe that another round of tax breaks for millionaires is what’s going to bring good jobs back to our shores, or pay down our deficit,” he said. He said that the economy’s woes were have been “building up over decades” and that it will take “more than a few years” to solve them.

Romney used the jobs report to paint Obama as a failure, calling the sluggish growth in jobs “simply unimaginable.”

“This president tried,” Romney said. “But he didn’t understand what it takes to make our economy work. I do.”