R epublican Mitt Romney vowed to step up coal production and President Barack Obama mocked him for opposing a windmill tax credit, in a rare debate over energy policy on the campaign trail.
Romney staked out a pro-coal stance in eastern Ohio, a mountainous region where he must do well to have a chance to win a swing state that went to Obama in 2008.
Appearing with Ohio Senator Rob Portman, whom he passed over as his vice presidential running mate in favor of congressman Paul Ryan, Romney said that if elected he would pursue a policy to take advantage of "all our energy resources."
"We have 250 years of coal. Why the heck wouldn't we use it?" Romney told coal miners wearing hard hats. "By the end of my second term, I make this commitment: We will have North American energy independence. We won't have to buy oil from Venezuela and the Middle East."
Obama took his campaign for re-election to Iowa, a state he won four years ago but which is now flirting with Romney. A big agricultural state, Iowa has enjoyed years of government subsidies for its corn production to make ethanol.
Obama is making a similar case for the state's windmills, saying he supports an extension for tax credits for wind energy manufacturers in Iowa and elsewhere. The tax credits expire at year's end.
In criticizing Romney for opposing the tax credits, Obama appeared to bring up an often-told tale about Romney, that he once put his dog in a container and strapped it to the roof of his car to go on a family vacation.
"During a speech a few months ago, Governor Romney even explained his energy policy this way: 'You can't drive a car with a windmill on it.' That's what he said about wind power. I wonder if he actually tried that," Obama said.
There was a jarring note on the campaign trail when Vice President Joe Biden told a rally in Danville, Virginia that if elected Romney would cut regulations on banks to the detriment of consumers.
"BACK IN CHAINS"
"They're going to put y'all back in chains," Biden told the crowd.
The Romney campaign, already bristling at an ad from a pro-Obama group that all but accused Romney of complicity in the death of a laid-off steelworker's wife, was livid, saying the Obama campaign had reached a new low.
"The comments made by the vice president of the United States are not acceptable in our political discourse and demonstrate yet again that the Obama campaign will say and do anything to win this election," said Romney spokeswoman Andrea Saul.
Romney is seeking to use the announcement of his vice presidential running mate, coupled with the upcoming Republican convention where they will be nominated as the party's candidates to face Obama and Biden, to give a spark to his campaign after he fell behind the president in several voter polls in recent weeks.
But there are questions as to whether Ryan, a conservative budget hawk from Wisconsin, will give the campaign a significant boost.
Although the Ryan pick energized Republicans, polls show a mixed picture so far among the electorate writ large as voters take stock of a budget proposal by Ryan filled with spending cuts that has been an easy target for Democrats.
A four-day bus tour by Romney, which has already motored through the swing states of Virginia, North Carolina and Florida, was ending in Ohio. The Republican's message here was aimed at convincing voters his energy policy would create jobs and ease unemployment.
Romney is now far more conservative in his views on carbon sources of fuel than when he was governor of Massachusetts in 2004 and unveiled a "climate protection policy."
Obama has pushed green energy policies as a way of weaning Americans off imported energy and reducing the carbon emissions blamed for global warming.
But not all his green moves have been successful.
A $500 million grant from his $862 billion economic stimulus in 2009 went to a solar panel company called Solyndra that eventually went bankrupt, at a loss for American taxpayers.