PORTSMOUTH, N.H. — President Obama delivered a rousing call to action to thousands of supporters Friday, fresh off his speech Thursday night at the Democratic National Convention.

“We’re going to have to work, because this is going to be a close election,” Obama said, to chants of “four more years” from the crowd.

As he did at the convention in Charlotte, N.C., Obama framed the election as a choice between “two fundamentally different visions” for America.

He said Republicans want to leave people to fend for themselves.

“When we work together we all do better,” he said. “America’s not just about what can be done for us. It’s about what can be done by us together as one nation and one people.”

An estimated 6,000 people attended the event on a field surrounded by the historic homes and buildings that make up the Strawbery Banke Museum.

Obama was joined by his wife, Michelle, and Vice President Joe Biden and his wife, Jill, in a rare joint campaign appearance. The visit by both couples showed just how close the election is shaping up to be, in New Hampshire and nationally.

Obama cited numbers released Friday morning that showed slow job growth continuing nationwide.

He said the country was losing 800,000 jobs a month when he took office at the start of 2009, and this is the 30th consecutive month of job gains.

“But that’s not good enough,” he said. “We need to create more jobs faster. We need to come out of this crisis stronger than when we went into it.”

Obama said he needs four more years to provide more opportunity in the economy. His plan, he said, includes investing in education and green energy, adding manufacturing jobs, and reforming the tax system and reducing the federal deficit without hurting the middle class.

“I’m not going to pretend that this path is quick or easy, and by the way I never have,” he said.

Obama said Republicans haven’t offered a specific alternative plan, and joked that they seem to think tax cuts and deregulation will fix everything.

“All they have to offer is the same prescription they have used for 30 years. Tax cuts, tax cuts, deregulation, oh and tax cuts,” Obama said.

Obama said he reduced taxes for middle-class families, but doesn’t believe that tax cuts for the highest earners will help the economy or reduce the deficit.

“We have been there. We’ve tried that. It didn’t work then. It’s not going to work now. We’re not going back. We are moving forward,” he said.

Obama paraphrased former President Clinton when he criticized Republican candidate Mitt Romney’s plan to reduce the federal deficit and cut taxes for the wealthy. “There’s a basic component missing from his plan’s math,” Obama said.

Obama praised Clinton for his speech at the convention Wednesday night, saying someone suggested making Clinton Secretary of Explaining Stuff. “I like that,” Obama said.

He also praised the convention speech given by his wife Tuesday night. “Wasn’t Michelle amazing?” Obama said, drawing a loud cheer. Many in the audience Friday said they were most looking forward to seeing and hearing the first lady.

Michelle Obama did not speak but waved from the stage with her husband and the Bidens, and greeted supporters at the end of the event.

Biden spoke briefly and praised the president for his compassion and courage.

Susan Yorston, 57, of nearby York Beach, Maine, said she was inspired by watching Obama’s convention speech late Thursday. “It was a little hard to get up this morning, but if he can do it, I can do it,” she said.

Berhanu Stevens, 10, Beti Stevens, 11, and Lily Kemp, 11 — all from Kittery and students at Shapleigh School — were excited to see the Obamas, even though it meant missing some school.

“I really like Barack Obama and Michelle and what he’s done for others,” Beti Stevens said.

“I want to see the kids,” Berhanu Stevens said. The first daughters, however, didn’t make the trip.

Beti and Berhanu Stevens, who were born in Ethiopia, said they especially admire the Obamas because they are African-Americans. The girls had promised teachers they would say hello to the president, and people in the crowd later gave Beti Stevens a boost so she could shake Obama’s hand.

Despite the enthusiasm and support in Portsmouth on Friday, Obama will have to work hard to win New Hampshire, said Pam Cote, 66, a retired nurse from York Beach.

“I don’t think the momentum is as good as it was before,” she said.

Cote volunteered for Obama in 2008 and attended Friday’s event to try to get enthusiastic again. “I’m a little disappointed,” she said.

She had hoped that the nation’s wars would end sooner, that there would be more jobs by now, and that the country would have a true single-payer health care system by now, she said.

Cote will likely campaign for Obama again in any case, she said. “What’s the alternative?”

New Hampshire has just four electoral votes — 270 are needed to win. But it is one of 12 states that easily could go either way, and both campaigns are focusing on every one of them.

The intense battle over New Hampshire is the reason that voters in southern Maine have seen so many presidential campaign ads in recent weeks. The candidates and their supporters are spending heavily on ads in the Portland market because of its reach into parts of New Hampshire.

Friday’s stop was likely as close as Obama will come to Maine before the election Nov. 6. Romney isn’t expected to visit Maine, either, unless the race tightens up.

Maine also has four electoral votes. Both Maine and New Hampshire voted for Obama in 2008.

Maine is considered a relatively safe state for Obama this year. New Hampshire is different in at least two ways.

It has historically voted Republican in presidential elections, while Maine has trended toward Democrats. And Mitt Romney has spent a lot of time in New Hampshire. He has a vacation home on Lake Winnipesaukee in Wolfeboro, N.H.

Staff Writer John Richardson can be contacted at 791-6324 or at:

jrichardson@pressherald.com