Correction: An earlier version of this article incorrectly stated that Greentech is under investigation by the Department of Homeland Security. The DHS inspector general has launched a preliminary investigation into whether an agency official improperly intervened on behalf of GreenTech and other firms. This reference has been removed.

On the issue of climate change, Democrat Terry McAuliffe has spent more time in the race for Virginia governor criticizing his opponent’s positions than defining his own.

McAuliffe has tried to draw a stark contrast with Republican Ken Cuccinelli II. He ridicules Cuccinelli’s skepticism toward the scientific consensus that people are warming the Earth.

But when pressed for detail about his own views, McAuliffe often sticks to broad outlines. Four years after his first run for governor, the Democrat has backed away from his opposition to coal-fired power, and he has newly embraced offshore drilling. He has declined to say where he stands on new emissions standards that the EPA is due to release Friday. He speaks broadly of the need for greater investment in green energy while also cautioning that coal jobs must be preserved.

McAuliffe’s tightrope walk results in part from an effort not to alienate the energy sector or the thousands of voters in southwest Virginia who work in the coal industry. At a time when Republicans are blitzing those Virginians with advertisements about the Obama administration’s “war on coal,” McAuliffe appears to be trying to keep his distance.

The Democrat also must navigate the challenging publicity surrounding his stewardship of GreenTech Automotive, an electric-car company under investigation by the Securities and Exchange Commission. McAuliffe has at times avoided promoting his own investment in green energy, presumably because it gives Republicans a chance to remind voters of his involvement with the troubled company.

Virginia's gubernatorial candidates Ken Cuccinelli (R) and Terry McAuliffe (D) share their positions on clean energy, coal, and job creation at a forum this summer at the George Mason School of Law. (Casey Capachi/The Washington Post, footage courtesy of Consumer Energy Alliance)

Mostly, when the topic of the environment arises, McAuliffe talks about Cuccinelli.

McAuliffe and his environmentalist supporters have characterized Cuccinelli as a science denier, as demonstrated by the legal challenge that Cuccinelli mounted soon after becoming attorney general in 2010 to the EPA’s decision to regulate greenhouse gases implicated in global warming.

Cuccinelli is also known for his controversial attempt to investigate a climate researcher at the University of Virginia. McAuliffe has said that Cuccinelli’s investigation of Michael Mann shows why the Republican would be “bad for business.”

At a recent appearance in Charlottesville with Mann, McAuliffe sought to draw a sharp contrast when he said: “That’s not a welcoming message to bring scientists and technologists and professors from all over the globe to come to Virginia when you know you will be harassed by the attorney general of the state. Not a welcoming message. We need to move away from that. ”

These talking points have attracted deep-pocketed support for McAuliffe from environmental activists, notably billionaire Tom Steyer, who is investing heavily in the race as a way to push climate change onto the national political stage.

The attacks also have put Cuccinelli on the defensive. After a recent energy forum, the Republican dodged a question from a reporter about whether he believes humans are responsible for global warming.

“Ken Cuccinelli is one of the most vocal climate-change deniers in the country,” said Jeffrey Gohringer, a spokesman for the League of Conservation Voters, which has poured $1.6 million into the race. “We can’t trust him to address a problem that he doesn’t even believe exists.”

But mostly, it is McAuliffe who appears caught between two constituencies.

The Democrat says he believes that humans have contributed to global warming, and he characterizes clean energy as a national security issue. To wean the United States from dependency on foreign oil, he has advocated more investment in green technologies, such as carbon capture and storage.

But McAuliffe has been harder to pin down on imminent EPA regulations that would limit carbon emissions at coal-fired plants, saying he wants to wait until the rules are issued. He has expressed concern about any regulations that would “significantly increase utility costs for Virginians or result in the closure of existing Virginia power plants,” a campaign spokesman said.

Similarly, in 2009, McAuliffe said he never wanted to see another coal plant open in Virginia. But this year, he was quoted by the Bristol Herald Courier as saying he wants to see the coal industry grow. He has also reversed his opposition to offshore drilling.

Cuccinelli has leaped at the chance to note those shifts. He and other Republicans have warned that McAuliffe’s recent support for coal is not to be trusted, given his alliance with Steyer and other environmentalist groups. He has suggested that McAuliffe would fall in line with the Obama administration’s push for strict new regulations that could hurt the industry and risk taxpayer money by steering subsidies to the fledgling renewable-energy industry.

“Terry’s GreenTech failure and Solyndra’s failure are stark reminders that government doesn’t pick winners, they pick losers, at your expense,” Cuccinelli said at the forum. “At taxpayers’ expense.”

Like McAuliffe, Cuccinelli says he supports a broad menu of energy options: wind, solar, nuclear and existing fossil fuels. But he and other Republicans say Virginians care much more about jobs and the potential cost of new environmental regulations than about global warming.

“In an economy crippled by long-term unemployment, I very much doubt climate change will be a top-of-mind concern for Commonwealth voters, much as the Walden Pond crowd hopes it would be,” Luke Popovich, a spokesman for the National Mining Association, said in an e-mail.

Last week, the Republican’s campaign blitzed the state with ads about a “war on coal” after word leaked about the EPA’s plans for new emissions standards. Industry leaders said the rules would effectively prohibit the construction of new coal-fired plants.

Cuccinelli has also taken McAuliffe to task for his investment in green ventures.

McAuliffe invested in two such ventures after losing his 2009 bid for Virginia governor: GreenTech and Franklin Pellets. McAuliffe initially intended that GreenTech manufacture electric cars in Virginia, but the company began production in Mississippi.

The former chairman of the Democratic National Committee also lobbied a top official in the Obama administration to remove obstacles to the firm’s ability to raise capital and create jobs — raising questions, and prompting investigations, about whether top officials improperly intervened.

Franklin Pellets is a partnership intended to produce wood fuel from timber waste on the site of International Paper’s former paper mill in Franklin and ship it to Europe from a storage facility leased at the Port of Virginia. To date, the company has not finalized plans to take over part of International Paper’s campus. McAuliffe’s promises that GreenTech would create thousands of American jobs and millions of American-made cars have also fallen short.

Cuccinelli said at a recent forum that the ventures are instructive of McAuliffe’s approach and that his record of mixing business with politics suggests he would lead Virginia down a path to ventures such as Solyndra, a solar panel company that cost federal taxpayers about $535 million before its bankruptcy.

“Will [Virginians] vote for someone who may enter office with a federal investigation hanging over his head?” Cuccinelli asked at the forum. “That would be a first.”