America is the land of the free, but environmentalists are determined to rule the air. The Environmental Protection Agency persists with expensive and unnecessary schemes to regulate harmless carbon dioxide — the stuff we and the plants breathe — and several energy companies and coal-producing states are making a final appeal to the courts to halt a deliberate attempt to seize authority the EPA was never meant to have.

A three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit will hear a petition Thursday from 15 states, mostly in the Midwest and the East, that would feel the impact of the EPA’s proposed Clean Power Plan to reduce carbon dioxide emissions 30 percent below 2005 levels by 2030 as a favor to the global “green” lobby. (Plants, which must have these “harmful” emissions to survive, would not be pleased).

The plaintiffs are asking the court to issue an “extraordinary writ” to halt the agency’s implementation of the new air-quality standards, which would force the shuttering of coal-fired power plants unable afford the necessary technological upgrades. The EPA scheme would pave the way for a major conversion to unreliable wind, solar and other forms of renewable energy so beloved by the environmental left. The American consumer would pay billions of dollars more for the electricity.

If the court rules for the EPA, the Constitution gets further shredding. “It is a remarkable example of executive overreach and an administrative agency’s assertion of power beyond its statutory authority,” says Laurence Tribe, the lawyer for the plaintiffs. “Indeed, the Proposed Rule raises serious constitutional questions.” These are the words of the man who tried to teach constitutional law to Barack Obama at Harvard. He is the lawyer in this case for the Peabody Energy Corp.

Mr. Tribe observes that by the agency’s own reckoning, the rule would eliminate the burning of coal for electricity generation in 12 states. Such drastic measures are the result of the agency seizing authority based on an obscure section of the 1990 Clean Air Act. The plaintiffs say the act allows the EPA to regulate stationary sources of carbon dioxide; the EPA argues it is authorized to regulate both source and emission, adding muscle to schemes to drastically cut carbon dioxide nationwide. That, Mr. Tribe says, is overreach — appropriating power and authority rightly belonging to Congress.

The president’s knowledge of constitutional law suggests he studied the founding document only to learn how to subvert it. He might flunk Mr. Tribe’s course now.