Obama briefly mentioned his storm efforts to the Ohio audiences, then offered his standard fare. “We know what change looks like and what he’s offering just ain’t it," he said.

He got his biggest cheers talking about the auto industry, and the Romney ad that suggests Chrysler policies will mean Toledo, Ohio, jobs will go to workers in China.

"It’s not true! Everybody knows it’s not true,’’ Obama said.

Romney Saturday told audiences how Obama told voters at a Springfield, Ohio, rally, Friday that they should vote for revenge.

The president was discussing Romney when he was interrupted by boos. “No, no, no -- don’t boo, vote,” Obama said. The crowd applauded. “Vote,” he urged. “voting is the best revenge.”

Romney seized on the remark Saturday, releasing an ad citing the remark and mentioning it in speeches.

"He’s asking his supporters to vote for revenge," Romney said in Dubuque . "I’m asking you to vote for love of country."

The campaign said the messages underscored the two campaigns’ different approaches. "The governor (Romney) was offering a positive message about change and President Obama was talking about voting for revenge, it’s a stark contrast,” Romney senior adviser Stuart Stevens said.

The Obama campaign defended the comment.

“It’s important to remember that the context of when the President said that was as he was laying out the fact that Mitt Romney is closing his campaign with an ad full of scare tactics that’s frightening workers in Ohio and thinking falsely that they’re not going to have a job,” said Obama spokeswoman Jen Psaki.

Romney got support in Dubuque from NASCAR legend Richard Petty , who said Iowa and North Carolina "messed up" in voting for Obama in 2008.

"It had four years to think about the mistake you made four years ago," Petty told the crowd.