CHARLOTTE, N.C. (AP) — Republicans and Democrats jockeyed for economic high ground in a Labor Day warm-up to the Democratic National Convention, with Republican Mitt Romney labeling the holiday “another day of worrying” for too many Americans anxious about finding a job. Supporters of President Barack Obama worked to put a glossy sheen on economic progress after offering a more muddled message over the weekend.

Obama addresses a United Auto Workers Labor Day rally in Toledo before getting his first look at the aftermath of Hurricane Isaac in a stricken parish outside New Orleans. He’s to meet emergency personnel who’ve been laboring since the storm hit last week to restore power and tend to thousands of evacuees from flooded areas.

Romney issued a statement marking Labor Day as “a chance to celebrate the strong American work ethic.” But he added: “For far too many Americans, today is another day of worrying when their next paycheck will come.”

Obama’s backers were up early to try a morning do-over of his supporters’ less-than-rosy answers Sunday when asked to answer the classic campaign question: Are Americans better off than they were four years ago?

“Absolutely,” said Stephanie Cutter, Obama’s deputy campaign manager, speaking on NBC’s “Today” show. “By any measure the country has moved forward over the last four years. It might not be as fast as some people would’ve hoped. The president agrees with that.”

Martin O’Malley, Maryland’s Democratic governor, had answered the same question with a “no” on Sunday before turning the blame to Obama’s Republican predecessor. Appearing Monday on CNN, O’Malley tried a more positive turn of phrase, saying: “We are clearly better off as a country because we’re now creating jobs rather than losing them. But we have not recovered all that we lost in the Bush recession. That’s why we need to continue to move forward” under Obama.

While the official convention program doesn’t start until Tuesday, delegations were gathering across Charlotte on Monday for state breakfasts. Convention officials were also hosting a Labor Day festival in downtown Charlotte featuring singer James Taylor and actor Jeff Bridges.

At a breakfast with the Iowa delegation, Los Angeles Mayor Antonio Villaraigosa, the chair of the convention, told about 60 members of the state’s contingent that Romney and running mate Paul Ryan would pursue massive tax cuts that would benefit only the very wealthy — stances that he said were far removed from their GOP predecessors.

“Ronald Reagan would turn in his grave listening to some of these people,” he said. “They’re so far out there.”

Villaraigosa told the Iowans that he spent 25 years as a community organizer and urged them to register new voters and recruit volunteers to help re-elect Obama.

“We’ve got our work cut out for us. We know that,” he said. “The country is evenly divided. It has been for a long time. So what are we going to do? This is going to be a working convention. Every one of you can sign up as a volunteer. In fact, I know you’re already going to volunteer.”

In Boulder, Colo., on Sunday, Obama warned a college crowd that “the other side is going to spend more money than we’ve ever seen in our lives, with an avalanche of attack ads and insults and making stuff up, just making stuff up.”

“What they’re counting on is that you get so discouraged by this, that at a certain point you just say, you know what, I’m going to leave it up to somebody else.” Obama did not mention his own side’s arsenal of negative advertising.

The Republican convention behind him, Romney was staying low for a few days, preparing for the October debates as Democratic conventioneers gathered for the opening of their event Tuesday.

Younger voters gave Obama a big boost four years ago and he can ill afford to see their support drop off in a tight election where the sluggish economy is the dominant issue in the nation and a specific drag to many young people coming out of college or trying to afford it.

But his campaign surely has a more immediate need for young people, too — helping to fill the seats for Obama’s address Thursday. With 6,000 delegates at the convention and thousands more attached to the event, Democrats hope to pack a nearly 74,000-seat outdoor stadium for the prime-time speech.

Obama deputy campaign manager Jennifer O’Malley-Dillon told Iowa delegates the campaign was hoping the rain would stay away when the president delivers his speech.

“If you believe in weather gods, you should pray to them,” she said.

San Antonio Mayor Julian Castro delivers the keynote speech on Tuesday, followed by first lady Michelle Obama’s remarks. Obama and Vice President Joe Biden will be nominated for second terms on Wednesday night, when former President Bill Clinton takes the stage as star speaker.

Keeping a strong focus on the economy, a new Obama campaign ad running in six closely contested states — Colorado, Iowa, New Hampshire, Nevada, Ohio and Virginia — claims Romney’s policies would “hit the middle class harder” and that he doesn’t see the “heavy load” the middle class is carrying.

Biden joined the fray, accusing Republicans of seeking to undermine the decades-old federal program millions of seniors rely on for health care. “We are for Medicare,” he said. “They are for voucher care.” That was a reference to a proposal in Congress by Wisconsin Rep. Paul Ryan, the GOP vice presidential nominee, to offer future retirees the option of buying health insurance with a government subsidy.

The president and vice president campaigned separately across three battleground states as delegates descended on the Democrats’ convention city before their first official meeting Tuesday in the Time Warner Cable Arena.

Biden’s itinerary, in particular, underscored the threat that a sluggish recovery and high, 8.3 percent unemployment pose to Democrats seeking another term in power. He was in Pennsylvania and Wisconsin, states that have received little attention previously as the candidates, their parties and outside allies concentrate on the areas of the country deemed most competitive. His presence suggested the race in both states was tightening.

Romney spent Sunday at his Wolfeboro, N.H., vacation home, leaving only to attend church services with his wife, Ann. Aides said he would spend much of the Democrats’ convention week preparing for three fall debates with Obama, beginning on Oct. 3.

Obama aides said they expected Romney and Republicans to outpace the president and his party in fundraising in August because Obama spent less time raising cash than in the month before, and because the GOP held its convention — usually a big money draw — in August.