"They promised to create 6 million jobs, and guess what? They're about 7 million short," charged Kerry, campaigning in a state that sided with Mr. Bush in 2000, but now has unemployment above the national average.
"They can't come here to Akron or to any other place in America and talk to you about all the jobs that they created, because they haven't," he added.
A few miles up Interstate 77 outside Cleveland, in Broadview Heights, Mr. Bush conceded the state has "pockets of unemployment that are unacceptable."
At the same time, he said, "the economy is strong and getting stronger," and accused his Democratic rival of proposing tax increases that would crimp the economy.
"He's not going to be taxing anybody in '05, because he's not going to win," the president added quickly to applause from his supporters in Broadview Heights. "We're going to win Ohio and we're going to win the country."
Kerry has said he would restore taxes to pre-Bush levels on people earning more than $200,000 to help pay for expanded health care coverage.
With little more than eight weeks remaining to Election Day, a Newsweek survey relased Saturday gave the president a lead of 52-41 over Kerry, with independent Ralph Nader at 3 percent.
A Time Magazine poll released a day earlier also made it an 11-point race.
The Newsweek poll of 1,008 registered voters was taken Thursday and Friday and has a margin of error of plus or minus 3 percentage points.
The poll also found that Mr. Bush's approval rating at 52 percent, the first time it has topped 50 percent in the magazine's surveys since January. Also, 53 percent said they wanted to see Mr. Bush re-elected.
Presidential candidates often enjoy a boost in support in polls taken in the wake of their party conventions. Sometimes that can portend victory - but such gains also can melt away rapidly in the heat of a fall campaign.
CBS News Correspondent John Roberts says, "The Bush campaign isn't putting much stock in (the new polls) ... though they're happy to have people talk about (them)."
Both sides downplayed the polls. "I've got a lot of work to do," Mr. Bush said at an Ohio ice cream shop.
Bush campaign manager Ken Mehlman said it's too soon to see a big convention bounce. He says a better indication should come from surveys next week.
Mehlman said he's still expecting a "topsy-turvey" campaign, with lots of ups and downs for both candidates.
Kerry spokesman David Wade said the election won't be decided on a couple of national polls. "This is a race that's going to be decided in battleground states," he said.
Mr. Bush and Kerry both chose Ohio for their stage at the beginning of the Labor Day weekend, traditionally viewed as the kickoff for the fall campaign.
No Republican - Mr. Bush included - has ever won the White House without carrying the state, but lingering unemployment and anger about jobs getting shipped overseas have made the state a tossup.
Both men campaigned across the northeastern, Democratic part of the state, signaling a desire by Kerry to maximize his support, and an attempt by the president to hold down his rival's margins.
"I believe we need a new direction for America's families, and together, we're going to put the middle class first and get our economy back on track," the Massachusetts senator said in the Democrats' weekly radio address.
Ohio had an unemployment rate of 5.9 percent in July, the latest available. The national rate was 5.5 percent the same month, dipping to 5.4 percent in August.
Mr. Bush seized onshowing 144,000 jobs were added to payrolls as evidence of an improving economy. Kerry said it merely confirmed that the president's term would probably end with a net loss of jobs, the first since the Great Depression.
Kerry also criticized Mr. Bush for thethat beneficiaries will confront next year - an $11.60 jump per month and the largest in the history of the program.
"Who are they going to send the bill to?" he said. "Are they going to send the bill to Halliburton? Are they going to send the bill to Ken Lay and Enron? You bet they're not. They're going to send the bill to our senior citizens."
An opponent of the Medicare prescription drug legislation that Mr. Bush signed earlier this year, Kerry criticized the administration for policies that block Americans from buying their medicine at lower cost in Canada.
For his part, Mr. Bush said the tax cuts he pushed through Congress had helped restore economic growth after recession and the terrorism attacks of Sept. 11, 2001.
"We have got a plan to make sure that people who want a job can find one. The plan says that in order to keep jobs in America, we got to keep your taxes low," he said.
"Running up the taxes on the people right now would hurt the economic vitality and growth."
Kerry has said he will roll back tax cuts on the wealthiest Americans, but will cut taxes further for the middle class.
"This is not the time to give tax cuts to the Bill Gates of the world," said Kerry's running mate, John Edwards, speaking in Newport, Wis., about the nearly $400 billion record deficit. He was on a bus tour Saturday through Wisconsin.
Vice President Dick Cheney, campaigning in Roswell, N.M., continued his criticism of Kerry's vow to build coalitions and work with the United Nations before going to war.
"We will never seek a permission slip to defend the United States," Cheney said on his fourth trip to New Mexico this year.
Kerry was making appearances Saturday in Akron and Steubenville.
From Broadview Heights, Mr. Bush was rolling through northern Ohio on a bus to Kirtland, and then flying to Erie, Pa., his final campaign stop before returning to the White House. On Sunday, the president is campaigning in Parkersburg, W.Va.