"The truth is, the only people who benefit from George Bush's Social Security scheme are the special interests," Kerry said in remarks prepared for a town-hall meeting in West Palm Beach, Fla., a battleground state rich in people keenly interested in the two pillars of retirement, Social Security and Medicare.
Mr. Bush, meanwhile, accused Kerry of sending "mixed signals" on the Iraq war that threaten U.S. troops' morale and undermine Iraqis' determination to face down insurgents.
"You cannot lead the war against terror if you wilt or waver when times get tough," the president said at a campaign rally in King of Prussia, Pa.
"My opponent is sending mixed signals,'' Mr. Bush said. "You cannot expect the Iraqi people to stand up and do the hard work of democracy if you're pessimistic about their ability to govern themselves. You cannot expect our troops to continue to do the hard work if they hear mixed messages from Washington, D.C."
Earlier Wednesday in New York, the president thanked Pakistan Gen. Pervez Musharraf for help in hunting down terrorists along Afghanistan's border, but he sidestepped thorny issues. Then he flew to the battleground state of Pennsylvania for rallies and a tour of storm-damage areas.
Kerry's two-day swing through Florida, which began Tuesday, follows deadly hurricanes that nearly halted polling and politicking in the state. Mr. Bush made his third campaign-season trip to Florida this week to assess damage caused by Hurricane Ivan. Kerry has been to the state that decided the 2000 election nine times this year.
Mr. Bush favors allowing young workers to create voluntary personal savings accounts with some of the money they now pay into the Social Security system, a change he insists will not increase payroll taxes or change benefits for retirees or near retirees.
Kerry, however, contended that diverting money from Social Security to private accounts was a "bad, old idea."
"That's not a plan, it's a rip-off," he said. "George Bush's scheme hurts seniors by cutting benefits, and it hurts our economy by increasing the deficit."
Kerry pointed to a study by Austan Goolsbee, a University of Chicago business professor, who studied a model that proposes workers set aside a small percentage of their pay in private accounts as a method to adjust Social Security to a rapidly graying population.
Goolsbee concluded that fees charged by financial companies could reap them hundreds of billions of dollars and eat 20 percent of the benefits in an account held by a worker making an average salary.
The Bush-Cheney campaign said Kerry hasn't explained how he'd meet the challenges posed to Social Security by aging Baby Boomers.
"His record is one of voting for higher taxes on current retirees and ignoring the needs of future retirees," said Bush campaign spokesman Steve Schmidt.
Kerry wants to bolster the retirement program by reducing the deficit and expanding the economy. Some experts say economic growth might be insufficient to cover future benefits because those benefits grow as wages increase.
The Massachusetts senator also wants to improve Medicare by retooling the recently passed prescription drug benefit to let the government negotiate for bulk discounts on drugs.
in Orlando and Jacksonville in Florida on Tuesday, promoting his health care plan and criticizing the president's conduct in Iraq.
Mr. Bush's record in Iraq means he "does not have the credibility to lead the world," Kerry told reporters. He also questioned the president's rebuff of a CIA intelligence survey. Mr. Bush said "they were just guessing as to what the conditions might be like."
"Does that make you feel safer? Does that give you confidence that this president know what he's talking about?" he asked supporters at a late-night rally in Orlando.