Donald Trump revealed Thursday that he has selected Scott Pruitt, the current Oklahoma attorney general, to run the Environmental Protection Agency. Pruitt is a curious choice because he has made a career of suing the EPA to block regulations designed to protect clean air and water. (Naturally, he also denies the existence of climate change.) As head of the agency, Pruitt will surely abolish myriad environmental regulations, justifying the rollback the same way he justified his many anti-EPA lawsuits—as a defense of states’ constitutional rights to control their own pollution.

Don’t believe it for a second. Pruitt is one of the phoniest federalists in the GOP—a party notorious for praising states’ rights yet backing expansive federal power when it suits them. At the same time that Pruitt supported states’ ability to regulate pollution within their own borders—and keep the federal government from regulating it for them—he argued that states have no right to legalize marijuana. His rationale for this apparent contradiction? Pollution isn’t especially harmful to other states. Marijuana is.

Pruitt’s pot hypocrisy is impossible to square with his own carefully cultivated image as a loyal defender of states’ rights. As Oklahoma AG, Pruitt set up a “Federalism Unit” to defend state sovereignty. Opposing breathable air and nontoxic water is not a politically viable position—but opposing federal overreach certainly is, at least in Oklahoma. So Pruitt, whose political career was financed by the oil and gas industries, framed his EPA lawsuits as a defense of state autonomy against an out-of-control federal government.

These lawsuits and legal complaints—some of which were literally written by fossil fuel companies—often read like treatises on the beauty of states’ rights. In suits attempting to block the EPA from limiting mercury pollution, decreasing ozone pollution, and reducing smog, Pruitt insisted that the federal government had no business regulating such pollutants. The power to keep America’s air clean, he declared in court, rested with the states. He used the same argument against the Clean Power Plan, which would cut back on carbon dioxide emissions from coal plants. The 10th Amendment, Pruitt asserted, gave states, not the EPA, the authority to reduce emissions—or not reduce them.

Of course, this claim is absurd on its face, because one state cannot emit pollution without affecting others. When Oklahoma spews ozone, it causes premature deaths in neighboring states. When Oklahoma emits carbon dioxide, it contributes to climate change, shrinking the shorelines of faraway states. That’s precisely why the federal government is tasked with regulating most pollution: Ozone, mercury, and carbon don’t care about state lines, making environmental protection an inherently interstate endeavor. The EPA has to take the lead in restricting harmful pollutants; otherwise, a few states could poison the air and water that all Americans rely upon to survive.

But there’s little use in debunking Pruitt’s 10th Amendment evangelism, because he doesn’t really believe it anyway. He essentially admitted as much in late 2014, when Pruitt teamed up with Nebraska’s attorney general to sue Colorado for legalizing marijuana. Pruitt argued that Colorado’s legalization had increased the flow of marijuana into his state, creating an interstate “nuisance.” He then asked the Supreme Court to rule that Congress must force Colorado to recriminalize marijuana because the drug remains illegal under federal law.

The shamelessness of this hypocrisy really is breathtaking. Pruitt had routinely argued that Congress lacked the power to regulate pollutants within his state. He had also sued to block the Affordable Care Act’s Medicaid expansion, asserting that Congress had no authority to make states expand their Medicaid programs. But now Pruitt claimed that Congress did have the power to commandeer Colorado’s state Legislature and demand that its lawmakers recriminalize marijuana. In fact, Pruitt declared that Congress had a legal requirement to intervene in Colorado’s political affairs and force the state to criminalize a certain substance because his state didn’t like it.

Ultimately, the Supreme Court refused to hear Pruitt’s case. Its nondecision was great news for actual defenders of state sovereignty. Had Pruitt prevailed, he would’ve seriously diminished states’ rights, removing the 10th Amendment safeguard that prevents the federal government from coercing states into enforcing federal regulations. His anti-marijuana crusade would have crushed state autonomy in a way that no EPA regulation ever could.

Thus, for all of Pruitt’s bluster about states’ rights, his real goals remain glaringly political: to minimize EPA regulation (as his coal and gas donors desire) while quashing the pro-marijuana movement (as his alcohol industry donors desire). Like much of Trump’s Cabinet, Pruitt is not so much outwardly corrupt as openly unprincipled—a politician who stands only for the things that lobbyists pay him to stand for.