(AP)-- Campaigning by bus through swing state Ohio, President Barack Obama cast his re-election bid as a bet on the American worker Thursday, even as he braced for a Friday unemployment report that will help set battle lines for the hot summer to come.
The monthly unemployment numbers could alter or harden voters' views of Obama's core re-election argument that he pulled the U.S. back from recession while Republican Mitt Romney embraces policies that led to an economic near-collapse. A weak report could undermine Obama's position, while improvement could help the president -- though concerns about jobs are sure to a major issue through Election Day.
Obama tellingly chose to start his summer of on-the-road campaigning in two political battleground states that have a rosier economic outlook than some parts of the nation. Both Ohio and Pennsylvania had unemployment rates of 7.3 percent in May, well below the national average of 8.2 percent.
"This is how summer is supposed to feel," Obama said, wiping sweat from his face he campaigned under scorching sun for four more years in office.
His trip through northern Ohio gave him a post-July 4 splash of Americana: Main streets and U.S. flags, cornfields and fruit stands, community soccer sign-ups and American Legion halls, small children climbing on fathers' shoulders to see the president's bus go by. Obama was greeted kindly wherever he went and bounded through his day, high-fiving the kids and hugging grandmothers.
Romney rolled his own bus tour through six states last month, including the two Obama is visiting this week. And more are certain to come in the next few months for both candidates.
As he kicked off Thursday's 250-mile trip in Maumee, Ohio, Obama said he had "refused to turn my back on communities like this one."
Romney, chiming in from his family vacation in New Hampshire, criticized Obama for hitting the road with "no new answers" on the economy.
The president, speaking at an early 19th-century museum complex dotted with red-white-and-blue bunting and American flags, claimed credit for Ohio's improving economy, especially its rejuvenated automobile industry. The White House said the Obama-backed auto bailout helped dramatically increase sales of Chrysler's Jeep Wrangler and Liberty, made in nearby Toledo.
Obama said Ohio's economic gains could be replicated nationwide.
"There are some folks who are betting that you will lose interest, that are betting that somehow you are going to lose heart," Obama said. "I'm betting you're not going to lose interest. I'm betting you're not going to lose heart. I still believe on you, I'm betting on you."
In an economic appeal to working class voters, the president also announced his administration was launching an unfair trade complaint against China with the World Trade Organization. The complaint centers on new Chinese duties on American-made cars that the U.S. contends violate international trade rules.
As his day of campaigning stretched into dusk, Obama took a fresh shot at Romney on taxes, saying the Republican's plan would cut taxes for the wealthy at the expense of education spending and health care for the elderly.
"I don't need a tax cut. Mr. Romney sure doesn't need a tax cut," Obama said in Parma.
And Obama defended his health care overhaul during his first campaign appearance since the law was upheld by the Supreme Court.
"The law I passed is here to stay," he said. "It is going to make the vast majority of Americans more secure."
Romney has vowed to repeal the health care overhaul if elected, and Republicans believe that position can be a winning one. But much of the attention since the ruling last week has been on debate within the party over whether the law's insurance mandate is a tax or a penalty. A tax, Romney said Wednesday, contradicting an adviser's comments of a few days earlier.
Friday's jobs report was on many minds, too. Obama aides have been anxiously awaiting the new numbers, which follow a dismal May report that showed an uptick in the unemployment rate to 8.2 percent and raised concerns about a further economic slowdown.
The latest economic indicators have been mixed. U.S. manufacturing shrank in June for the first time in nearly three years, according to a report this week. Private payroll provider ADP reported Thursday that U.S. businesses added 176,000 jobs last month, better than the revised total of 136,000 jobs it reported for May. But shoppers pulled back on spending in June, leading to sluggish retail sales during the month.
Obama already faces an uphill battle convincing some voters he is the right steward for the economy. An Associated Press-GfK poll released last month found that more than half of those surveyed, 52 percent, disapproved of his handling of unemployment, compared with 45 percent who approved.
Some Ohio voters said the auto bailout was still a plus for Obama. "The bailout will certainly help him. It's definitely working," said Linda Schneider of Maumee.
But Thomas Hutton of Toledo said it the bailout would not be a defining campaign issue. "It's a side issue. The big ones are the economy and health care," he said.
Republicans dispatched former Minnesota Gov. Tim Pawlenty and Louisiana Gov. Bobby Jindal, two potential vice presidential nominees, to counter Obama's appeal to voters in some of the same towns where the president was stopping.
"We should all bet on the country, but we shouldn't double down on Barack Obama," Pawlenty said Thursday. "He's had his chance. It's not working. And we need to get it moving in a different direction."
Ohio Republican Sen. Rob Portman, yet another potential Romney running mate, wrote a column in an Ohio newspaper Thursday accusing Obama of implementing policies that "make it harder, not easier, to create jobs here in Ohio and around the country."
The bus trip marked a new phase of Obama's re-election campaign as he takes a more retail-oriented approach before the September Democratic convention in Charlotte, N.C. Among his events in Ohio Thursday was an ice cream social in Sandusky and remarks in a park in Parma, a suburb of Cleveland.
Obama, dressed casually in a short-sleeved shirt and khaki pants, sprinkled his campaign speeches with personal references, telling the crowd about his oldest daughter Malia's 14th birthday and promising his popular wife Michelle Obama would come see them in Ohio soon.
As Obama made his way from Maumee to Sandusky, Ohio, he made an unannounced stop at Kozy Corners, a diner in the town of Oak Harbor, where he greeted the lunchtime crowd. He bought fruit at a roadside stand along the shores of Lake Erie, where he picked up a dozen ears of corn, plus some peaches and cherries. And he drank a beer at a bar in Amherst and chatted with patrons.
Obama also sought to extend the reach of his bus tour by taping interviews with six Ohio TV stations.
Friday's schedule includes a stop at an elementary school in Poland, Ohio, near Youngstown, followed by a speech at Carnegie Mellon University in Pittsburgh.
Recent polls by Quinnipiac University found that Obama held a 9-percentage-point lead over Romney in Ohio and a 6-point lead in Pennsylvania. Obama won both states in the 2008 election.