President Obama brought his reelection message to a manufacturing town in this important battleground state Wednesday, hoping to build enthusiasm for his campaign in the region where he will accept the 2012 Democratic nomination this summer.

Obama toured a Daimler Trucks plant and touted the company’s recent growth and commitment to developing alternative fuel technologies, which the Obama administration has promoted as a strategy to wean the country off foreign oil at a time of rising gasoline prices.

The appearance was an official White House event, but it had the feeling at times of a campaign rally, coming a day after the national spotlight on the GOP Super Tuesday primaries in 10 states. Workers at the plant, wearing navy-blue union T-shirts reading “Buy American” and “Buy Union,” interrupted the president with chants of “Four more years!” after he said that achieving energy would require more than one term.

“I love this state. Everyone here is so nice, so welcoming,” Obama said. “Even folks who don’t vote for me.”

It was Obama’s 13th appearance in North Carolina, a state where he eked out a victory in 2008 over John McCain by a mere 14,000 votes. Though the president will deliver his nomination acceptance speech Sept. 7 in Charlotte, about 15 miles from the Daimler plant, he’ll have his work cut out for him to carry the Tar Heel state again.

Unemployment in North Carolina is 9.9 percent, the fifth-highest rate in the nation, and in 2010, Republicans won control of both chambers of the statehouse for the first time in more than 100 years.

Meanwhile, 51 percent of state residents disapprove of Obama’s handling of the economy, with 43 percent approving, according to a new Elon University poll published this week. Although that marked an improvement from the fall, when 57 percent of North Carolinians disapproved and 37 percent approved, the disapproval number remains higher than the national average.

Perhaps trying to ensure he doesn’t lose any more support, Obama joked with his audience that the color of his tie looked a bit like the Carolina blue of the University of North Carolina, but also like the deeper blue of arch-rival Duke University.

“I don’t want to get in trouble with anybody!” Obama said with a laugh.

The Obama campaign has kept a close eye on North Carolina, with the president making two appearances in the state last fall during his national jobs tour. First lady Michelle Obama and Vice President Biden have both delivered fundraising speeches here in recent weeks.

Democratic Reps. Heath Shuler and Mel Watt of North Carolina traveled with Obama aboard Air Force One to the event Wednesday, and Gov. Bev Purdue (D) and Charlotte Mayor Anthony Foxx (D) were in the audience.

As the Republican presidential candidates continue to slog through a bruising primary season, Obama campaign officials said Wednesday they are focused on building their organization in the critical swing states.

The campaign has opened nine offices in North Carolina, and a recent Obama campaign event at North Carolina Central University featured actress Gabrielle Union, Obama adviser Valerie Jarrett and campaign manager Jim Messina.

“While they destroy each other, we’re building our campaign nationally,” senior campaign adviser David Axelrod said of Republicans during a conference call with reporters Wednesday. “We’re fortified for a tough race. . . . The longer the Republican primary goes, the longer we have to continue to build.”

The campaign said it will release a 17-minute documentary video next week by director Davis Guggenheim focused on the president’s first term. Guggenheim was the director and executive producer of the Academy Award-winning documentary “An Inconvenient Truth” with Al Gore.

At the Daimler plant, the president continued to push back against GOP criticism that his administration is not doing enough to protect consumers from a recent spike in gasoline prices.

Obama announced new tax credits for vehicles that use advanced technologies — from the current amount of $7,500 to $10,000 — and a $1 billion grant program for up to 15 communities that seek to support the widespread use of advanced vehicles.

Daimler already is partnering with the Energy Department to increase fuel efficiency of large trucks, and Obama highlighted the plant’s hiring of 1,000 workers in 2011, including many who previously had been laid off, after production ramped up to meet increased demand.

But Republicans continued to blame the president’s policies for the pressure at the pump. Republican National Committee Chairman Reince Priebus said Obama has broken his 2008 campaign promise to keep prices low.

“There is no reason to believe that today’s promises will be any different and is just another reason why North Carolinians can’t afford a second term of Barack Obama,” Priebus said.