The insinuation by the Democratic nominee is subtle but unmistakable: George W. Bush, the president of the United States, is lazy.

Outside Youngstown, Ohio, on Sunday, John F. Kerry mocked Bush for attesting in Thursday's presidential debate -- 22 times -- that his administration is engaged in "hard work." "I welcome hard work," Kerry said. "I like hard work. I think hard work is a good thing."

Hours later in Cleveland, former congressman Louis Stokes (D-Ohio) warmed up a crowd for Kerry by deriding what he called Bush's aversion to "hard work."

In New Hampshire on Monday, Kerry ridiculed Bush for having "photos taken reading books to kids" but not doing the more difficult work of improving education. He also took a shot at Vice President Cheney, who went fishing Monday. "If he goes with the same intelligence we went to Iraq with, he's going to have a bad day," Kerry said.

Never mind that Bush maintains a more hectic campaign rhythm than his challenger. The Kerry campaign is trying to capitalize on Bush's obsession during the debate with saying how difficult his job is. "Saturday Night Live," which gave Al Gore a world of hurt in 2000 by lampooning his sighs during a debate, opened its new season with a skit in which a Bush impersonator lamented: "Frankly, I don't know why my opponent wants this job, because it's hard!"

"So your plan is to crush terrorism by coming in on Saturdays?" asked the character playing moderator Jim Lehrer.

The Bush character replied, with reluctance: "If that's what it takes."

The Kerry campaign is trying to contrast Bush's alleged lethargy with Kerry's vigor. "We're not going to look back on this race knowing we got too much sleep," spokesman David Wade said. "I can say for a fact that John Kerry will not spend 40 percent of his presidency on vacation."

Kerry is on some tenuous ground as he makes the suggestion of sloth. The Massachusetts senator has been off the trail 63 days this year, including 13 crucial days since his nominating convention. This past weekend is the first since the fall campaign began on Labor Day that Kerry has campaigned both days. In contrast to the punctual Bush, Kerry is often late, and his schedule allows plenty of dawdling time. And while campaigning he missed 177 of 194 votes in the Senate, Republicans point out.

The Bush campaign has also tried to poke fun at Kerry's leisure pursuits, cutting an ad showing him windsurfing and frequently suggesting that his time in the surf has left him detached from reality. Bush routinely speaks of Kerry's tendency to "wilt" and "waver," in contrast to his own firm resolve.

But Bush's relaxation requirements have a particular resonance among Democratic partisans after the Michael Moore film "Fahrenheit 9/11" showed scenes of Bush golfing, fishing and touring his ranch in the days before the Sept. 11, 2001, attacks. "With everything going wrong, he did what any of us would do," Moore intoned. "He went -- on vacation."

Bush has spent all or part of more than 40 percent of his days as president at one of his retreats: Camp David; Kennebunkport, Maine; or Crawford, Tex. He has spent so many days clearing brush on his ranch that some journalists joke that he is having extra brush flown in. He is known to prefer day trips to overnights so he can sleep in his own bed.

Bush, evidently sensitive to the slacker accusation, has not been seen playing golf in a year, opting for the more vigorous sport of mountain biking. But he suffered a setback in the debate when he repeatedly spoke of his arduous tasks. "In Iraq, no doubt about it, it's tough. It's hard work. It's incredibly hard," he said at the start of the debate, before repeating a variation on that theme 21 times, even saying of his effort to comfort a soldier's widow: "It's hard work to try to love her as best as I can."

Being seen as lazy can be devastating. The election to the Senate of Joseph I. Lieberman (D-Conn.) in 1988 is attributed largely to an ad he ran portraying the GOP incumbent, Lowell P. Weicker Jr., as a sleeping bear who missed many votes.

Kathleen Grant, a Kerry supporter from Iowa, last month blamed his swoon in the polls on his work ethic: "I have been seeing him on vacation, playing football and other things, but time is running down."

Both campaigns are moving, energetically, to dispel any notion of sloth. After the debates end next week, both plan to spend virtually every day hopping from airport to airport, holding three or four rallies each day. Leaving New Hampshire on Monday, Kerry looked wistfully toward the woods. "I wish I could spend the day and go up in the mountains," he said. But not this time. "Twenty-nine hard days ahead of us," he said. Very hard.

President Bush talks to Sen. Charles E. Grassley (R-Iowa) in Des Moines before signing the Working Families Tax Relief Act of 2004.Sen. John F. Kerry takes questions from students during a talk about medical research at Winnacunnet High School in Hampton, N.H.