Tuesday marks a milestone for John Kerry (search), when the man who has often been at his best while giving a formal speech delivers the last one planned for his presidential campaign.

Kerry's last address tackles one of the defining issues of the campaign — which candidate can best protect Americans from another terrorist attack. For the final week, Kerry will try to sell his candidacy at political rallies that are traditionally less about policy than about inspiring voters.

But Kerry's rallies often sound a lot like speeches. He reads off statistics, quotes from inside-the-Beltway reports and even assigns homework to the crowd.

"I'm so glad you came here tonight, but I'm going to give you some homework," Kerry said Thursday night. His rowdy crowd fell silent as he went on explaining their assignment.

"You've got to go out of here tonight, and every single one of you — if we want to change the direction back to common sense, if we want to be fair to average folks in this country, if we want to create those jobs here in America again, if we're going to do stem cell research (search), if we're going to have after-school programs, if we're going to have health care that's affordable and accessible to all Americans, if we're going to be fiscally responsible and put this country on track again — then we have to work our tails off for the next 12 days," Kerry said. "Every single one of you. You've got to go out and knock on doors."

President Bush has a completely different style than Kerry. He likes to tell jokes and deliver punchy one-liners that bring home his points.

Kerry tends to wade deeper and describe his positions in more complex terms. He's more proper and formal, more academic. His supporters say he sounds like a president.

"Bush only tells jokes because he doesn't have anything else to say," said Kerry supporter Allison James, after sitting through a Kerry rally in Reno, Nev., Saturday night.

Kerry's style is illustrated by a story he's been telling recently on the campaign trail about a woman who sent a message to him through one of his staffers: "Tell the senator we've got his back."

Kerry delights in this casual phrase, a grin bursting on his face when he tells it, and he throws it back at his audiences at nearly every stop. "I've got YOUR back," he says.

But there's a formality in the way that Kerry speaks, even when he's saying something as casual as this. He says the phrase slowly and carefully pronounces each word, so it doesn't sound like it would if it came from a friend or a teammate who made the promise in a huddle.

Kerry's at his best stylistically when he reads a formal, prepared speech, particularly in an academic setting on a heavy topic like foreign policy. He's given several that have framed his campaign:

— In a January 2003 speech at Georgetown University, he encouraged Bush to recruit allies for the fight against Iraq and warned him not to "rush to war."

— On the anniversary of Bush's declaration of an end to major combat in Iraq last April, Kerry took the podium at Westminster College in Missouri. He said the United States had not succeeded in its mission and faced a "moment of truth" that called for a new direction.

— Just before the first presidential debate last month, Kerry told an audience at New York University that Bush was ignoring the truth of the deteriorating situation in Iraq. After months of trying to voice a clear stance on the war, Kerry sharpened his criticism of the president, accusing him of "stubborn incompetence," dishonesty and colossal failures of judgment.

Kerry inserts portions of these speeches and others into each of his rallies. He uses carefully selected facts and figures, all aimed at persuading his audiences to remove the sitting president from office.

Kerry tries to break up all the serious talk with some lighter local references. Sometimes they work, sometimes they don't.

"I called Sander Levin," Kerry told a Michigan audience Monday night, referring to the hometown congressman. "And I said I was running for the highest office in the land. He said that's great, but I don't really know why you want to be Michigan football coach."

The wisecrack brought some laughter. It also brought some boos from the rival Michigan State fans. "Or state," Kerry added. "Or whatever."