Oskaloosa, Iowa (CNN) - Kicking off the second day of his three-day bus tour across Iowa, President Obama shifted his message from drought relief to renewable energy, and even found a way to connect wind power to Mitt Romney's now-infamous dog Seamus.

Speaking in a state that gets 20 percent of its electricity from wind power, Obama on Tuesday criticized his Republican rival Mitt Romney for opposing tax credits for renewable energy companies.

"During a speech a few months ago Governor Romney even explained his new energy policy this way, I'm quoting here: 'You can't drive a car with a windmill on it,'" Obama said. "That's what he said about wind power: 'You can't drive a car with a windmill on it.' I don't know if he's actually tried that. I know he's had other things on his car."



The story of Romney lashing his dog's cage to the roof of his car for a cross-country trip has become popular amongst the governor's detractors, and the president's veiled reference drew laughter from the crowd of more than 800 gathered to hear him speak.

The not-so-subtle dig at his opponent came while the president was ticking off a laundry list of the wind industry's bona fides, most often followed by criticisms of Romney's stance on renewable energy.

"Homegrown energy, like wind energy, is creating new jobs all across Iowa and all across the country, and guess what, Governor Romney said let’s end the tax credits for wind energy production, let's get rid of them," Obama said. "He said that new sources of energy like wind are imaginary. His running mate calls them a fad."

The Romney campaign disputed the president's claims, pointing to job losses in the wind industry under Obama as one example of how the president's policies have hurt the expansion of renewable energy.

"Mitt Romney is a strong supporter of wind power and appreciates the industry's extraordinary technological progress and its important contributions to America's energy supply," Romney campaign spokesman Ryan Williams said. "Unfortunately, under President Obama's approach, the industry has lost 10,000 jobs while growth in wind power nationally has slowed every single year of his term. Mitt Romney will instead set the industry on a course for success and growth by promoting policies that remove regulatory barriers, support free enterprise and market-based competition, and reward technological innovation."

Representatives for the industry argue that any shrinkage in domestic wind-related employment is due largely to the recent economic slowdown and believe the overall picture is of an industry that continues to grow dramatically.