"I don't know if he's actually tried that. I know he's had other things on his car," Obama joked, referring to the often-repeated tale of a Romney family road trip with their dog, Seamus, in a carrier strapped to the roof of the car.
"But if he wants to learn something about wind, all he's got to do is pay attention to what you've been doing here in Iowa," the president said.
The federal government says between 6,000 and 7,000 jobs in Iowa are related to the wind industry and that the state gets about 20 percent of its electricity from wind.
In a bipartisan vote last week, the Senate's tax-writing committee agreed to renew dozens of tax breaks for businesses like biodiesel and wind energy producers, provisions opposed by many conservatives but that also have critical support from some Republicans, like Sen. Charles Grassley of Iowa.
"Unlike my opponent, I want to stop giving $4 billion in taxpayer subsidies each year to big oil companies that have rarely been more profitable, and keep investing in homegrown energy sources like wind that have never been more promising," Obama told about 850 people in Oskaloosa, where stacked hay bales and an old, red pickup truck provided the requisite rural backdrop.
The presidential debate moved across five swing states Tuesday, as both campaigns operated on full strength for a second day.
Ohio was on Romney's schedule, the final day of a multistate bus tour, with three stops in the state. Running mate Paul Ryan, the Wisconsin congressman, was dispatched to court voters and donors in Colorado and Nevada. For all the advantages of having a running mate to share the workload, the Republicans are working through the challenge of planning double the events, coordinating messaging on the road, handling new security stresses and simply getting to know each other.
Vice President Joe Biden kept up his criticism of the Republican ticket and their support for a House GOP budget plan, telling supporters in rural southern Virginia Tuesday that Romney and Ryan are "good men" but with "fundamentally flawed judgment."
Romney was addressing what he says is the administration's "war on coal." Obama's administration has pushed ahead with regulations on new power plants, making it harder to build new coal-fired plants. That has hurt places like Beallsville, in coal-rich eastern Ohio.
Ryan was to promote Romney's "all-of-the-above" energy approach during his event in Lakewood, Colo., before heading to Las Vegas to highlight Obama's response to the state home foreclosure crisis. The congressman is also expected to attend a private fundraiser with conservative mega-donor Sheldon Adelson.
Little more than 80 days remain in a campaign dominated by the weak economic recovery and a national 8.3 percent jobless rate. Polls taken before Romney added Ryan to his ticket showed Obama with a slender advantage in a contest that will be decided in eight to 10 battleground states.
Ohio is likely the most difficult to win of the four must-win states Romney toured by bus; he also visited North Carolina, Virginia and Florida. But as Ryan visits other battlegrounds more than 1,000 miles away, Romney's team has showed some signs of the strain:
• Some of Romney's staff in Florida were on the phone Monday offering advice to Ryan's team in Iowa, while planning events coming up in Colorado and Nevada.
• There were none of the new Romney-Ryan placards at Romney's Florida event or Ryan's Iowa appearance Monday, leaving attendees waving older Romney-only signs.
• Security officials didn't set up enough metal detectors to sweep the thousands of people who showed up in Florida, leaving many stranded outside barricades or on the street.
• At the Iowa State Fair, a protester managed to climb onstage with Ryan before his new security team dragged her away.
Meanwhile, plans continued for the Republican convention opening in less than two weeks in Tampa, Fla., as New Jersey Gov. Chris Christie was announced as the keynote speaker. Romney's campaign said Florida Sen. Marco Rubio will introduce Romney at the convention. Rubio campaigned with Romney in Miami on Monday.
Both had been talked about as possible Romney running mates.
For his part, Obama is expected to call on Congress to extend expiring tax credits for wind energy production. The White House on Tuesday pointed to a new Energy Department report saying wind power installations "surged" in 2011, but warning that uncertainty over extending the wind energy tax credits threatens to "dramatically slow" the industry.
The report, released annually, emerged as Obama campaigned through politically competitive Iowa, a leader in wind power production. The report estimated that 75,000 U.S. jobs now depend on wind power, including several thousand in Iowa.
Romney has opposed extending the alternative energy credits, but several Iowa Republicans Iowa Gov. Terry Branstad and Grassley among them favor the credits. That may give Obama the chance to create a local wedge issue to appeal to unaligned voters.
Romney spokesman Ryan Williams said the Republican candidate would boost the wind industry by "promoting policies that remove regulatory barriers, support free enterprise and market-based competition, and reward technological innovation."
Obama's campaign also released a Web video Tuesday chiding Romney for ads in which he accuses the White House of stripping work requirements from the welfare law. Independent fact checkers have found the premise of the ads to be false.
The video shows Romney asking his opponent to "take your campaign out of the gutter." Then it urges, "Mr. Romney ... take your own advice."