This is just an example of regulating interstate commerce, which is one of the powers delegated to the federal government by the constitution.
Forgoing this regulation of interstate commerce in order to save people's jobs, however, is not one of the powers delegated to the federal government by the constitution.
Why are conservatives (who are supposedly in favor of strict readings of the constitution) bitching about this?
Tucker Case - Tard magnet.
UPDATE 1-US axes permit for Arch's giant mountain coalmine | Reuters
St. Louis-based Arch said it would vigorously defend the permit in court. EPA's revocation of the permit blocks an additional $250 million in investment and 250 jobs, the company said.