Both candidates devoted Friday to the Buckeye State, considered the top prize in the states considered battlegrounds.
At a rally in Hilliard, Obama attacked a Romney radio ad running in Ohio that accused the administration of selling out Chrysler employees. The ad says the president sold the company to Italians -- the Italian automaker Fiat is now the majority owner -- who plan to move Jeep production from the United States to China.
"I know, you know, we're close to the election, but this isn't a game. These are people's jobs, these are people's lives," Obama said. "You've got folks who work at a Jeep plant who have been calling their employers, worried, asking is it true, are our jobs being shipped the China? And the reason they've been getting these calls is that Governor Romney is running an ad that says so. It's not true. Everybody knows it's not true. The car companies themselves have been telling Governor Romney to knock it off."
In Springfield, Obama noted that a lot of people in an overflow crowd at Springfield High School were too young to vote, "but you're not too young to make sure your parents vote."
"You're not too young to tell your uncles and aunties and grandpas and grandmas to vote, because this is a big election. And if we win Ohio, we're going to win this election," he said.
Inside, Obama told the crowd: "In four days, you've got a choice to make -- it's not just a choice between two parties or two candidates. It's a choice between two different visions for America."
"It's a choice between going back to the top-down policies that got us into this mess -- or the middle-out, bottom-up strategies that have gotten us out of this mess and are going to keep us going."
In Hilliard and Springfield, Obama spoke about the death and devastation left by Hurricane Sandy earlier this week.
"[What's] interesting is, during these kinds of crises, these disasters, as tough as it is and as sad as it is, we're also inspired because we see heroes running into buildings and wading through water to save their fellow citizens," Obama said in Springfield. "We see neighbors helping neighbors cope with tragedy. We see leaders of different parties working to fix what's broken, not to score political points. We see a spirit that says no matter how bad a storm is, no matter how tough times are, we're going to make it because we're all in this together."
"We rise or fall as one nation and as one people," he said to applause.
Obama's motorcade to the high school encountered several protesters holding anti-Obama signs mostly focused on the attack on the U.S. Consulate in Benghazi, Libya, in which the U.S. ambassador and four diplomatic employees died.
"Media do your job," read one sign. "Angry Ohio patriot," another read.
A third had photos of Obama and Secretary of State Hillary Clinton with the caption "Pretty little liars," a riff on the ABC Family teen series of the same name.
Romney, meanwhile, presented himself as the candidate of change in next week's election.
Delivering a speech in titled "Real Change from Day One," Romney was greeted in West Allis, Wis., by thousands of supporters chanting "four more days," the Milwaukee Journal Sentinel reported.
"Four years ago, candidate Obama promised to do so very much, but he has fallen so very short," Romney said in remarks prepared for delivery. "The question of this election comes down to this: Do you want more of the same or do you want real change?"
While Wisconsin has not gone to a Republican presidential nominee since Ronald Reagan in 1984, Romney said the state might be the one to put him over the top, USA Today reported. The visit was his first to the state since he selected Wisconsin Rep. Paul Ryan as his running mate.
Vice President Joe Biden also was on the stump in Wisconsin.
At the Westside Family Restaurant in Beloit, Biden shook hands and posed for pictures before settling down with a cheeseburger, fries and a soda.
At a nearby elementary school, Biden drew cheers and chants of "USA!" from students playing outside.
Romney wrapped up his Friday at a rally in West Chester, Ohio, with many of his big-name surrogates in attendance, telling supporters "we're going to take back the White House."
"It's good to be in Ohio and in [House Speaker] John Boehner's hometown," Romney said. "This is the state we have to win." No Republican has won the White House without winning Ohio since Abraham Lincoln.