President Obama's stranglehold on the union vote seems to be diminishing from the 2008 levels.

For the first time ever the UMWA will not be supporting a candidate in the presidential election.

The United Mine Workers of America enthusiastically supported Barack Obama's presidential campaign in 2008, but this year the union and its disgruntled members don't plan to back Obama's re-election bid.

Caputo told National Journal he couldn't remember a time when the UMWA — with more than 100,000 members in 2008, the last year the union updated its numbers — did not endorse a presidential candidate.

Obama's GOP opponent Mitt Romney has been claiming that Obama's Environmental Protection Agency is waging war on coal with too many regulations.

"Our members count on coal-fired power plants and burning of coal to keep jobs," Caputo said. "We're a very Democratic union and we try to listen to the rank and file. They've sent a clear message that they're not supportive of the environmental rules that are being put in place."

"Throughout Appalachia where Ohio, Pennsylvania, and West Virginia converge, the coal industry's disgruntlement with Obama is plastered on yard signs and billboards."

One billboard near the West Virginia-Pennsylvania border, sponsored by a coal-industry group, tells drivers they are entering "the Obama administration's no jobs zone."

In a close election year, the loss of these 100,000 voters and their families and friends could have an effect on the outcome in Ohio, Pennsylvania and West Virginia.