Democrats John Kerry (search) and John Edwards (search) rolled their post-nomination campaign into the heart of Pennsylvania, pitching their presidential ticket to independent voters in this battleground state.

On the first day of a two-week bus tour that will take the running mates through 21 states from coast to coast, Kerry visited thousands of supporters gathered Friday in front of the capitol of a state courted and coveted by Republicans and Democrats.

Kerry tailored an environmental message to sportsmen.

"This is one of the great preserves that cares about hunting and fishing and I say to you — as a hunter, as a fisherman — we need to preserve the habitat," the Massachusetts senator said. "We need to pass it on to our children in better shape than we were given it by our parents."

His pitch to independent and undecided voters included a strong emphasis on defense and security in an age of terrorism.

In remarks prepared for a rally in Greensburg, Pa., Kerry struck a familiar theme from his convention speech earlier in the week: America can do better.

"We are less than 100 days away from the election," Kerry said. "We all know elections are about choices and choices are about values. In the end, it's not just policies and programs that matter. The president behind the desk must be guided by principle."

Retired Gen. Merrill A. McPeak (search), who was Air Force chief of staff during the first Gulf War, said Saturday in the Democrats' weekly radio address that he withdrew his support from President Bush (search) to support Kerry on the strength of Kerry's wartime service and experience in Vietnam.

"The real deal for me is not whether a strategy or a plan or an idea is Republican or Democrat, but whether it makes us safer," he said. "And it means an awful lot to me that John Kerry fought for his country as a young man."

McPeak also questioned the president's "grudging cooperation" with the commission investigating the Sept. 11 terrorist attacks.

Bush fought back Friday while on his own Midwest campaign swing, charging that Kerry had "no record" of reforming America's intelligence capability during his eight years on the Senate Intelligence Committee. Bush's advisers are studying the Sept. 11 commission's recommendations to restructure intelligence forces.

Kerry singled out veterans as he surveyed a crowd packed in front of the Pennsylvania capitol that, by his estimate, reached 18,000 to 20,000. He vowed to stop Al Qaeda terrorists, a refrain repeated from a speech delivered Thursday earlier in Boston as he accepted the party's presidential nomination.

Kerry told The Associated Press in his first interview as the Democrats' presidential candidate that he would put the Sept. 11 attacks' suspected mastermind on trial in U.S. courts as the "fastest, surest route" to a murder conviction.

Usama bin Laden should be tried in New York City, Virginia and Pennsylvania, Kerry said.

Kerry concluded his Harrisburg remarks by urging supporters to ask their conservative friends to consider him.

"This outcome is much more in your hands than in ours," he said. "We need you to talk to your neighbors, talk to your friends, talk to the people who consider themselves to be conservatives. Talk to the people who may be in the middle of the road and aren't sure which way to go."

Kerry's stop in Harrisburg ended a day that saw the caravan of buses, security and support vehicles travel through Massachusetts, Connecticut and New York. The campaign was heading across Pennsylvania and into West Virginia and Ohio on Saturday.