As a law professor, I taught the nation’s first environmental law class 45 years ago. As a lawyer, I have supported countless environmental causes. And as a father and grandfather, I want to leave the Earth in better shape than when I arrived.

Nonetheless, I recently filed comments with the Environmental Protection Agency urging the agency to withdraw its Clean Power Plan, a regulatory proposal to reduce carbon emissions from the nation’s electric power plants. In my view, coping with climate change is a vital end, but it does not justify using unconstitutional means.

Although my comments opposing the EPA’s proposal were joined by a major coal producer, they reflect my professional conclusions as an independent legal scholar. I say only what I believe, whether I do so pro bono, or in this case having been retained by others. After studying the only legal basis offered for the EPA’s proposed rule, I concluded that the agency is asserting executive power far beyond its lawful authority.

The Clean Power Plan would set a carbon dioxide emission target for every state, and the EPA would command each state, within roughly a year, to come up with a package of laws to meet that target. If the agency approves the package, the state would then have to impose those laws on electric utilities and the public.

The agency would effectively dictate the energy mix used in each state and leave the state with essentially no choice in implementing its plan. But Supreme Court precedent settled over two decades ago in New York v. United States (1992) and reaffirmed by a 7-2 vote as recently as 2012 in NFIB v. Sebelius, the ObamaCare decision, holds that such federal commandeering of state governments defeats political accountability and violates principles of federalism that are basic to our constitutional order.