McCain airs new radio ad in Pa. attacking Biden's 'clean coal' comment

The campaign for John McCain has launched a new Pennsylvania radio ad that attacks the Democratic presidential ticket for opposing new coal plants.

The ad cites comments made by Democratic vice presidential nominee Joe Biden at a campaign event in Ohio, where the senator tells a supporter he and Barack Obama will not build anymore coal plants. 

The one-minute ad touts coal's importance to the state's economy and to the country's quest for energy independence before replaying Biden's remarks. 

"Obama, Biden and their liberal allies -- too risky for our jobs, our economic future,"  the ad says.

The McCain campaign and Pa. GOP have seized on Biden's remarks, using them to gain support in coal-heavy western Pennsylvania, where support for Obama is already soft.