John F. Kerry, deviating from his plan to speak optimistically during convention week, said Republicans and independents should rethink their support for President Bush or suffer the consequences of more expensive prescription drugs, inferior health care coverage and gravely damaged relations with U.S. allies.

Visiting the state that delivered Bush a 537-vote victory and, thus, the presidency in 2000, Kerry said, "I am not exaggerating when I tell you . . . never in 35 years have I seen the United States as . . . derided and disrespected as we are today."

Kerry then asked Sen. Bob Graham (D-Fla.), a finalist in the vice presidential search, to elaborate. Bush has "erected a giant billboard recruiting al Qaeda on the main street of virtually every city in the Middle East and Central Asia," Graham said. "Is that the type of leadership we want to ratify for another four years?"

Earlier in the event at the Kennedy Space Center, Kerry praised Graham for his courage and leadership in voting against the congressional resolution authorizing the war in Iraq. Kerry voted for it.

The comments from Kerry and Graham offered a stark contrast to the upbeat message the Democratic ticket is demanding for the convention and planning for his acceptance speech Thursday.

Kerry flew into Florida early Monday to talk about the unbounded possibilities of space and scientific exploration, and to campaign in one of the most competitive states. It is all part of his countdown to the convention. Next stop: Norfolk, to talk about national security.

At the town hall event, Kerry spent most of his time talking about health care, as several Democrats complained about rising premiums and shrinking benefits. One man spoke about the fear of losing the prescription drug benefit provided by his employer in 2006 when Medicare starts offering its own coverage. "Are you terrified of that happening?" Kerry asked the crowd, which included many seniors. "You should be. There is nothing to stop them from dropping you."

Democrats, including Kerry, are warning that employers that offer drug coverage as part of their health plan will drop, or curtail, it , forcing some seniors to buy into Medicare's less generous program. Republicans say new federal subsidies will entice most employers to maintain the drug benefit.

Meanwhile, near his home town of Raleigh, John Edwards grappled with a hoarse voice because of a minor cold at his last event before heading to Boston on Tuesday afternoon. The vice presidential candidate talked at a forum about the importance of the private sector and the government staying on the cutting edge of technology and research to compete globally. "When we lag, it makes it very difficult for us to compete. It's absolutely critical that we not be falling behind," he said at the North Carolina Biotechnology Center at Research Triangle Park.

Edwards said that he and Kerry are opposed to human cloning but that the government has to come up with some ethical guidelines and "make decisions on how far we can go" in ethically controversial scientific areas.

After the event, Edwards said in satellite interviews with local affiliates that he and Kerry would not indulge in Bush-bashing during their respective speeches to the convention. "We intend to focus on our positive vision for the country, what it is we want to do. I think most of the people in America know what the problems are with this administration and this president. What they want to hear from us is what our alternative vision for the country is and how we can make things better for the country, not just in the rhetoric but in real terms. . . .

"All I can tell you is, you won't hear it from me and you won't hear it from John Kerry. I have no way to control other people."

Edwards planned to spend the rest of the day working on his speech. Aides said he will do no further public events until he addresses the convention Wednesday night.

Romano reported from North Carolina.

Sen. John F. Kerry spoke with supporters in Florida about the possibility of increased prescription drug costs.