President Obama recently announced that his administration would begin regulating carbon emissions from power plants. McCarthy, currently the agency’s top air quality regulator, would be responsible for implementing those regulations if confirmed as EPA administrator.

Several Republicans have said although McCarthy is qualified for the position, they would not support her nomination because of Obama’s “war on coal.” Manchin joined Republicans Thursday in making this argument. Manchin is from one of the largest coal-producing states.

“Coal is America’s most abundant, most reliable and most used energy source,” Manchin said. “Ninety percent of America depends on coal for their energy. ... All we’re asking for is to have a partnership to keep the lights on.”

Republicans agreed to hold an up-or-down vote on her nomination as part of a deal to avoid Senate rules changes limiting the minority's right to filibuster executive branch nominees.