John F. Kerry returned to the political wars Tuesday, firing a preemptive shot at next week's Republican National Convention here with a warning that four days of "slogans and personal attacks" cannot cover up a four-year record of economic failure.

Speaking to a supportive audience at a campus a few blocks south of Madison Square Garden, where the GOP will nominate President Bush, the Democratic challenger argued that Republicans are responsible for "four years of lost jobs, lower wages, higher health care costs and tax cuts for the few."

"At every step of the way," he said, "George W. Bush has put the narrow interests of the few ahead of the interests of most Americans."

After two days of rest at his home in Boston, Kerry refocused his campaign on the core domestic issues of jobs and health care. He made no explicit reference to the controversy over his Vietnam service record that has dominated media coverage of the campaign for the past 10 days, and the ad campaign sponsored by other veterans of the Swift boat squadrons that patrolled the Mekong Delta 35 years ago.

Campaign aides gave reporters a compilation of 37 news articles and editorials decrying the ads sponsored by Swift Boat Veterans for Truth. In an obvious reference to the charge his campaign has made that Bush supporters are behind the veterans' attacks, Kerry said Republicans are "misleading the American people, hiding behind front groups, saying anything and doing anything to avoid the real issues that matter, like jobs, health care and the war in Iraq."

Kerry's audience greeted that statement with a standing ovation -- the same response given to his often-delivered stump speech declaration that "I defended this country as a young man, and I will defend it as president."

In a talk to a Philadelphia fundraiser on Tuesday night, Kerry repeated his charge that "the Bush administration is hiding behind this front group." The reason Bush will not condemn the ads, Kerry said, is that "the Bush administration can't talk about its record."

Kerry addressed his criticism of U.S. involvement in the Vietnam War after he returned from combat there. "You may not have agreed with me, but I stood up and was counted, and that's the kind of president I will be," he said.

In introducing Kerry to the Philadelphia crowd, Pennsylvania Gov. Edward G. Rendell (D) asked, "Who served this country better during the Vietnam War -- John Kerry or George Bush? Case closed."

Bush campaign spokesman Steve Schmidt called Kerry's remarks "stunningly hypocritical" because Kerry has benefited from independent groups on the left that Schmidt said make "baseless and untrue" charges about Bush. "John Kerry tried to present himself as a victim as a way to avoid talking about the issues," he said.

The setting for Kerry's kickoff speech in a pre-convention week of fundraising and campaign appearances that will take him across the country to California was a basement meeting hall at the Cooper Union for the Advancement of Science and Art, an honors college that provides free tuition to about 1,000 highly qualified undergraduates headed for careers in art, architecture and engineering.

The Great Hall, as it is called, was the site of a famous address by Abraham Lincoln early in 1860 -- an oratorical triumph credited with establishing his credentials for the presidency. As Kerry noted, four other successful presidential hopefuls -- all of them Republicans except Grover Cleveland -- spoke at Cooper Union, adding, "I hope to make the score 4-2."

Kerry's return to economic and health care issues is timed for the impending release of Census Bureau statistics that are expected to show a rise in poverty and an increase in the number of Americans without health insurance.

"This administration has weakened our middle class, weakened our economy, neglected the crisis of health care and turned away from the American dream of growth and opportunity for all," he said.

Kerry did not expand his menu of policy proposals. They include tax subsidies for job creation and tax credits for middle-income families. On health care, Kerry would have the federal government take on the costs of catastrophic illness, a step he said would save employers and workers as much as $1,000 a year in premiums.

Kerry running mate John Edwards took the Democratic ticket's economic message to Columbus, Ohio, to address a state AFL-CIO convention, Workers cheered his vow that a Kerry-Edwards administration could help revitalize struggling middle-class communities.

The Bush administration's policies "lift up people at the top, but they make life harder for people trying to make a living every single day," Edwards said as convention attendees waved signs reading "Take Back Ohio." The state went to Bush four years ago.

"Are the people of Ohio going to rehire a man who cost them 230,000 jobs?" Edwards asked, drawing a unified "No!" from the audience.

Bruce Rees, 50, a machinist from Dover, Ohio, said he is tired of "seeing the job loss that's going on in the nation and in Ohio, specifically."

"It's terrible for the small towns," he said. "I thought [Edwards] had a positive message about bringing work back to this country."

As he has for the past several days, Edwards called again for Bush to denounce an ad that has questioned Kerry's military service. "Every day these ads go on and the president refuses to say, 'Stop these ads,' we are learning more and more about the character of George W. Bush."

Staff writer David Nakamura, traveling with Edwards, contributed to this report.

In a speech, John F. Kerry says the GOP is responsible for "four years of lost jobs, lower wages, higher health care costs and tax cuts for the few."