Politicians are fond of recalling historical figures on the campaign trail - Washington, Lincoln, Roosevelt - as if the mere mention puts them into elevated company.

But there is a problem for John McCain in this Walt Disney World hotel when he reminisces about an idea that John F Kennedy and the Republican leader, Barry Goldwater, once shared of flying around the country for a series of town hall debates. Barack Obama, whom McCain is trying to entice into a series of such encounters, was just two when Kennedy was assassinated in 1963. McCain was already flying combat aircraft.

The age difference is one of the sharpest contrasts between Obama and McCain in an election campaign that is shaping up to be a referendum on a large sweep of America's political history.

At 71, McCain has lived through much of it, as was made apparent in his first ad for the general election, released yesterday. The Republican relives his experiences in Vietnam war. "I hate war," he says. "I'm running for president to keep the country I love safe."

But it emerges during this audience with Florida media chiefs that McCain is not just old, but cranky. Asked about his opposition to a $2bn plan to save the Everglades, supported by Florida's Republican governor, McCain demands: "Tell me what that bill was?" Then he turns on the questioner. "You just answered your own question," he snaps.

McCain's confusion is puzzling. This is his 18th visit to Florida since the campaign began and the Everglades is of big concern to voters. There is a front page story about Everglades preservation in that day's Miami Herald. McCain was due to make his first visit to the region yesterday.

"I am in favour of doing whatever's necessary to save the Everglades," McCain says. "But I will not vote for bills that have projects and other things on them that have not gone through the proper scrutiny."

It's an anaemic response for a candidate who has been heavily promoting his environmental credentials in an attempt to appeal to independent voters. It's also unlikely to be popular in Florida, which McCain has targeted as a battleground state against Obama.

Since March, when McCain became the last Republican left in the race for the White House, Democratic activists have fretted that the gruelling primary campaign would drain off energy and resources from the presidential race.

But Obama emerged from 16 months of combat with Hillary Clinton a more assured candidate and his campaign staff a well-oiled political machine.

McCain, though better rested, seems out of practice. Unlike Obama, whose staff line the route to every public appearance with campaign signs and cheering crowds, McCain, the former pilot, seems to fly under the radar.

On the loungers by the pool, no heads turn as McCain walks by en route to the darkened ballroom where he is to address his select audience.

McCain is struggling to build excitement about his candidacy. At his meeting here, he tries out a new strategy for countering Obama's powerful message about change. A McCain White House, he promises, will be about reform.

McCain also tried to inject some excitement into a speaking style that critics, and even his own camp followers, admit is stilted by ignoring the speech scrolling on autocues at the back of the room. But his delivery was no match for Obama's soaring oratory.

His 25 years in Congress provides a lot of potential material for his opponents. The steady criticism from the Obama camp has made it difficult for McCain to get his own message out to voters, and avoid being branded an appendage of the George Bush presidency.

Obama enjoys a narrow lead or is running even with McCain in the national polls. He has done even better on fund-raising. Last month, his best for fundraising, McCain took in $21.5m. Obama took in $55m in his best month, last February, and that was at a time when he was competing for Democratic donors.

But Florida, McCain hopes, could be different. McCain leads Obama in the polls in this battleground state, and he is working methodically to go after disaffected Clinton supporters.

He started this week at a meeting of Puerto Rican community leaders. Puerto Ricans are an increasingly important voting bloc and McCain managed to make some headway, impressing the audience with his credentials. "Obama is a person we didn't know till he got into the race. We don't know what he brings to the table," said Mildred Fernandes, a local official who is backing McCain.

But it's not yet clear that voters are getting to know McCain any better, or like him more when they do.