“For someone who makes the point that she’s not from Washington, she looked very much like she’d fit in very well there when you see how she brings the attacks,” Mr. Axelrod said. “They all felt very familiar to Americans who are used to this kind of thing from Washington.”

Advisers to Mrs. Clinton said that she stood ready to help the Obama-Biden ticket, but they urged the campaign not to overestimate the impact Mrs. Clinton could have, noting that she had other commitments this fall, like campaigning and raising money for Senate candidates. Obama aides said the Clinton trip had been in the works before Ms. Palin was named the running mate.

Still, Mo Elleithee, a Clinton spokesman, said he believed she could make a difference with some voters who feel lost in the current economy and who want to see a federal role enacting universal health insurance.

“Anyone who was inclined to support Hillary Clinton typically did so because of her focus on middle-class, bread-and-butter issues,” Mr. Elleithee said. “Her message for Barack Obama on those issues could certainly help the Democratic ticket at the ballot box.”

The Obama camp also plans to keep Mr. Biden campaigning steadily in swing states. Obama advisers said that one advantage they had was that Mr. Biden, as a six-term senator and former presidential candidate, is well-prepared for his single debate with Ms. Palin, in October.

With both conventions seen largely as successes for their tickets, the importance of the three presidential debates  the first of which is Sept. 26  and the one vice-presidential debate become even more crucial for either side to gain a political advantage, Democratic strategists and elected officials said.

Mr. Obama, speaking to reporters on Thursday at a campaign stop in York, Pa., brushed aside any worry that he might have about Ms. Palin’s criticism of his biography and political record in her convention speech.