Scott Pruitt enjoyed owning a AAA baseball team here, but he is having as much fun as Oklahoma’s attorney general, and one of the Obama administration’s most tenacious tormentors. The second existential challenge to the Affordable Care Act began here.

In the first, decided in June 2012, the Supreme Court saved the ACA by reading it imaginatively. The court held that although Congress could not, in the name of regulating commerce, penalize people for not engaging in commerce (buying insurance), the penalty linked to the individual mandate actually could be considered – although Congress did not so consider it – an exercise of Congress’ enumerated power to tax.

That same year, Pruitt lit another fuse, this one involving statutory rather than constitutional construction. He filed a suit that in June may contribute to the most seismic domestic development of 2015.

The suit asks the court to read the ACA unimaginatively, as meaning what it plainly says: Subsidies, in the form of tax credits, are available only to persons who purchase insurance through exchanges “established by the state.” Thirty-seven states have refused or failed to establish their own exchanges. The justices may be disinclined to use the ACA’s legislative history, or the candor of MIT’s loquacious professor Jonathan Gruber, to inform their deliberations. If, however, the justices do, they will see that Gruber, an ACA architect, says it was written to “squeeze the states” into establishing exchanges: “If you’re a state and you don’t set up an exchange, that means your citizens don’t get their tax credits.”

If the court holds that the ACA means what it plainly and purposively says, then billions of dollars have been disbursed through federal exchanges contrary to the law. The ACA will be crippled until Barack Obama negotiates help from a Republican-controlled Congress.

The Founders’ bargain, Pruitt says, was that the states would surrender some sovereignty in exchange for representation in the federal government. But the growth of federal power has tended to reduce states to administrative extensions of the federal government, leaving them with “pre-emption without representation.” So Pruitt has established within his office a “federalism unit” aimed at revitalizing federalism as a system of “vertical checks and balances.”

Oklahoma is among 24 states in a suit initiated by Texas Attorney General (and Gov.-elect) Greg Abbott charging that Obama’s unilateral changes in immigration policies are unconstitutional. The complaint is that Obama has injured these states by usurping the legislative power of Congress, in which the states’ interests are represented, and by creating, through executive fiat, policies that will impose substantial costs on the states.

Another target in Pruitt’s sights is the Environmental Protection Agency, which claims to have discovered in the Clean Air Act of 1970 a hitherto unnoticed authority perhaps sufficient to eliminate existing coal-fired power plants. Joined by 16 other state attorneys general, Pruitt argues that the federal government has the power to institute a national energy policy, which implicates the entire economy. But it cannot do so, pre-empting various of the states’ powers, simply by locating authority in the creative reading of a 44-year old statute.

And then there is the matter of puddles. Pruitt and other attorneys general are resisting the EPA’s and the Army Corps of Engineers’ contention that the 42-year old Clean Water Act has a hitherto unsuspected capaciousness. The act, which allows regulation of “navigable waters,” was passed under Congress’ power to regulate interstate commerce, so “navigable waters” have been understood to be those suitable for transporting people and products between the states.

But M. Reed Hopper and Todd F. Gaziano of the Pacific Legal Foundation, writing in The Wall Street Journal, say the EPA now wants to control not just wetlands and other non-navigable waters but any water or normally dry land with a “hydrological connection” to actual navigable waters. These include, Hopper and Gaziano say, “arroyos in the desert as well as ditches and culverts hundreds of miles from” actual navigable waters. Pruitt and other attorneys general are contesting this bureaucratic imperialism whereby the EPA, by aggregating almost all the nation’s water and much of its land into EPA-designated “ecoregions,” could regulate – and stifle – much of the nation’s economic activity.

The good news about the ACA, immigration and the EPA is that federalism remains a fact. Come January, federalism’s vitality will be an increasingly inconvenient truth for Obama. Twenty-seven states will have Republican attorneys general who can try to restrain the federal Leviathan much as the Lilliputians restrained Gulliver.

© 2014, Washington Post Writers Group