Seeking to sustain the energy from their national convention in Boston, the newly minted Democratic ticket arrived here Friday at the start of a two-week, coast-to-coast campaign trip, with John F. Kerry telling a throng of supporters that they "deserve a president who fights as hard for your job as he fights for his job."

But President Bush answered back on a campaign swing timed to coincide with the end of the Democratic convention, barnstorming through the Midwest and attacking Kerry as a senator who has accomplished little in two decades and cannot be trusted to reorganize the nation's intelligence services.

After spending convention week at his ranch in Crawford, Tex., Bush set off through four battleground states this weekend with aides saying he will use the month to outline a second-term agenda. But with his advisers determined to blunt any momentum Kerry may have developed in Boston, the president turned his sights to his challenger during a rally at Southwest Missouri State University.

"My opponent has good intentions, but intentions do not always translate to results," Bush said. "After 19 years in the United States Senate, my opponent has had thousands of votes, but very few signature achievements."

More than 10,000 people greeted Kerry and John Edwards and their families midafternoon here in Scranton, many having waited for several hours as the Democratic team and its 17-vehicle caravan launched a bus, boat, plane and train trip that will take the two candidates to 22 states in their bid to deny Bush a second term.

"These are dangerous times today," Kerry told the audience. "We're living in a world that's changed dramatically from the world of four years ago, and we deserve leadership that tells the truth to the American people and helps America act like a beacon to the world."

An even bigger crowd awaited Kerry and Edwards on Friday night at the state capitol in Harrisburg. There, Edwards said the president had reacted to the Democrats' convention with more attacks. "Here we go again," Edwards said. "Same old, same old thing. . . . Are you sick of it?"

Friday's exchanges signaled that there would be no significant lull in politicking in early August, with both sides planning intensive campaigning and the Republicans seeking to build anticipation for Bush's convention in New York at the end of August. Kerry will cut back as the GOP convention nears, but his two-week marathon coming out of the convention will set a new standard for endurance in presidential campaigning.

The two sides also returned to the airwaves after a week-long cease-fire for the convention. The Bush campaign aired a TV spot in which military and terrorism images give way to those of happy families, while a narrator says the world can sometimes "terrify. We depend more than ever on our values. . . . We need a sense of purpose, a vision for the future, the conviction to do what's right."

With the Kerry campaign off the air for the next month, the Democratic National Committee launched what it says will be at least a $50 million ad campaign with clips from Kerry's acceptance speech in Boston.

That effort will be financed in part by surplus funds accumulated by the Kerry campaign before he officially accepted the nomination. Campaign officials said Friday that Kerry raised a record $5.7 million Thursday through the Internet.

In Scranton, Kerry devoted most of his remarks to economic and domestic issues, but in an interview with the Associated Press he sounded a tough line on terrorism and said that, if Osama bin Laden is captured, the terrorist leader should be put on trial for murder in U.S. courts, not before an international tribunal.

Kerry, Edwards and their families arrived here running well behind schedule after an early morning rally in Boston and a stop in Newburgh, N.Y., where Edwards and his wife, Elizabeth, celebrated their 27th anniversary as they always do, with a meal at Wendy's.

Kerry and Edwards will campaign jointly or separately in virtually every battleground state over the next two weeks in an effort to seize the advantage in a race that has remained extremely close since Kerry wrapped up the nomination in March.

"No wonder they call this 'The Electric City,' " Kerry said, beaming, as he looked up and down a street jammed with supporters waving American flags, red, white and blue pompons and holding up placards of support. The crowd filled the openings of a local parking garage and looked out from windows in the federal building across from the courthouse where the rally was staged.

As he did in his acceptance speech Thursday night, Kerry hit hard on the theme of values and on the attacks by his opponents. Saying that values are more than slogans, he said, "We're both so tired, as you are, of politicians who run around and they throw this pablum at you, and you get these 30-second negative advertisements and these one-minute negative advertisements, everybody trying to destroy each other when we're trying to build up the United States of America."

The Democrats got an early start after a late night of speeches and celebration, kicking off their post-convention tour with an outdoor rally near Boston's FleetCenter.

"We're going to restore trust and credibility to the White House," Kerry told several hundred supporters as he launched what the campaign has dubbed its "Believe in America" tour. Reprising another line from his acceptance speech, Kerry said, "Help is on the way for the average person."

Standing in the shadow of Bunker Hill and the Old North Church that figured so prominently in the American Revolution, Kerry summoned up the patriots whom he said had risked everything to build the country. Then, in a reference to the lanterns that set Paul Revere off on his famous ride, Kerry joked, "They had better intelligence back then than we do today."

Kerry and Edwards were joined by their wives and families, as well as by Boston Mayor Thomas M. Menino and actor Ben Affleck, a Bostonian who was so ubiquitous at convention events that Kerry joked, "Between the two of us, John Edwards and I decided Ben Affleck had about four more hours of TV than we did."

Among those in the audience was Norman Conklin, 72, a Korean War veteran from Boston, who said he thought that Kerry, through his convention speech, had reached veterans with his strong statement of support for veterans benefits and his own experiences in Vietnam.

But Conklin said he hopes Kerry could recapture some of his campaign style from the Iowa caucuses. "I think he loosened up during Iowa -- and then after he won the nomination, he got uptight again," Conklin said. "I think now he is starting to get relaxed. That's what people need to see."

Staff writers Howard Kurtz in Washington and Mike Allen, traveling with Bush, contributed to this report.

Shaking hands at a Missouri college, President Bush challenged his Democratic opponent's accomplishments as a U.S. senator.With his Democratic nomination now official and the Republican convention approaching, John F. Kerry prepares to leave Boston to stump with running mate John Edwards.John F. Kerry is greeted by 10,000 people in Scranton, Pa., in a midafternoon stop on a 22-state tour, launched right after the Democratic convention.