Coal supporters put pressure on White House

In a letter to President Obama, 410 elected Democratic officials, including 12 former members of Congress, called on the administration to lay out an energy agenda that includes "clean" coal.

"From a policy perspective, there is no realistic path forward to a clean, low-carbon world that does not include clean, low-carbon coal," the elected officials said in the letter.

"Thus, the sustainable coal agenda is not only compatible with your clean energy and climate agenda, it is essential to it."

The majority of those who signed the letter were state officials. They joined under the CoalBlue Project, which pushes a bipartisan commitment to sustainable coal for the future.

Environmentalists cringe at the term "clean coal," highlighting the impact of mining on streams, lakes and wildlife, among other effects.

In recent months, the debate over a proposed Environmental Protection Agency rule, which would designate coal ash as a hazardous substance, has intensified.