This commentary originally appeared in Real Clear Policy on May 20, 2015.

Those alarmed over growing federal encroachment on the states and their citizens found a plethora of reasons to condemn Chief Justice John Roberts's 2012 opinion upholding Obamacare. Less noticed was Roberts's practical roadmap for future state resistance to federal overreach. Roberts wrote, "In the typical case we look to the States to defend their prerogatives by adopting ‘the simple expedient of not yielding' to the federal blandishments when they do not want to embrace the federal policies as their own. The States are separate and independent sovereigns. Sometimes they have to act like it."

Three years later, states appear to be getting Roberts's message. Three weeks ago, Governor Mary Fallin (R., Okla.) issued Executive Order 2015-22, regarding Oklahoma's compliance with the EPA's Clean Power Plan (CPP), which would limit carbon-dioxide emissions from existing fossil-fuel-fired power plants. Fallin labels the CPP a set of regulations that seeks "to go beyond" the EPA's "traditional authority and regulate all aspects of state energy systems." Arguing that "the EPA has exceeded its authority under the Clean Air Act" (the 1970 federal law from which EPA claims authority for the CPP), the executive order prohibits Oklahoma's Department of Environmental Quality from participating in any manner with the development of plans to implement CPP regulations in the state.

Fallin goes further. Under the proposed CPP, states are asked to submit State Implementation Plans (SIPs) "to ensure full compliance with the new federal mandates." If the CPP is adopted this summer, as is anticipated, Fallin pledges in the executive order that she "will not submit" a SIP "to ensure Oklahoma's compliance with such a clear overreach of federal authority."

The Oklahoma governor's bold action did not take place in a vacuum. Far from it. Nine days after Fallin issued her executive order, Texas governor Greg Abbott flew to Washington to meet with Senate Majority Leader Mitch McConnell and Texas senators John Cornyn and Ted Cruz to discuss Abbott's forecast of the CPP's "grave consequences for the State of Texas." Abbott's press advisory states that "The EPA's newest suite of rules, led by the Clean Power Plan, seeks unprecedented control over the State's energy mix that will certainly result in higher energy prices for Texans … killing jobs and stagnating Texas' unprecedented economic growth."

While Abbott was in Washington, lawmakers in the Texas House of Representatives were considering HB 3590, a bill that would require Texas, like Oklahoma, to "just say no" to EPA's request that it submit a SIP for the CPP. The rationale for state resistance is summarized by my Texas Public Policy Foundation colleague Kathleen Hartnett White: "The EPA's attempt to commandeer state governments to mandate what the EPA itself has no authority to mandate should be resisted as soon as possible on every level. Hopefully, federal courts will stop the clock on the EPA's impossible timelines until full judicial review is complete."

Texas and Oklahoma are not alone. According to one survey, there are today 32 states "in which elected officials (e.g., legislatures, governors, and/or attorneys general) have expressed firm opposition" to the CPP.

This flurry of state activity supports Majority Leader McConnell's March 19 letter to the National Governor's Association, about which I have written here. The most toxic effect of the CPP, according to McConnell, is the precedent that SIPs would establish, "allowing the EPA to wrest control of a state's energy policy if they or any other federal agency become dissatisfied" with a state's progress in cutting emissions. The EPA, McConnell concludes, will view state submission of a SIP as providing the agency with "broad new authority to control the state's energy future."

These uprisings in the states are having their effect on the national legislature. Just last Wednesday, several U.S. senators proposed legislation to combat the EPA's latest attempt to reduce greenhouse gases at existing power plants. Senator Shelley Moore Capito (R., W.V.), who heads the Senate Environment and Public Works Committee's Clean Air and Nuclear Safety Subcommittee, along with six other senators, introduced the Affordable Reliable Energy Now Act (ARENA). In a press advisory, Capito writes, "President Obama's misguided ‘Clean Power Plan' threatens to drastically reduce coal-related jobs, increase energy prices and reduce reliability. After carefully considering the economic and legal implications of this unprecedented proposal, the need for action is clear."

ARENA would extend the CPP's compliance deadlines, including SIP deadlines, pending review by federal courts. It would ensure that no state could be forced to implement a SIP or a Federal Implementation Plan if that state's governor concludes that so doing would harm the state's economy, lessen the reliability of the state's electricity system, or raise consumers' electricity bills. It also would prohibit the EPA from withholding federal highway funds from states found not to be in compliance with the CPP. Finally, and perhaps most importantly, the proposed bill would mandate that the EPA report to Congress the amount of greenhouse-gas emissions that the CPP is forecast to reduce as well as the methodology grounding the EPA's conclusions. This last provision offers a desperately needed reality check: As McConnell states in his letter to the governors, "the EPA admits that the 'climate' benefits of the CPP cannot be quantified." Moreover, the EPA has "refused to estimate the impact [the CPP] would have on global temperatures or sea levels."

One can only wonder at Chief Justice Roberts's reaction to these state efforts to "act like" the "separate and independent sovereigns" that the Constitution intends them to be. One can also wonder whether Roberts's counsel to states was sparked by what Founding Father John Dickinson observed in 1788: "The government of each state is, and is to be, sovereign and supreme in all matters that relate to each state only. It is to be subordinate barely in those matters that relate to the whole; and it will be their own faults, if the several states suffer the federal sovereignty to interfere in the things of their respective jurisdictions" (emphasis supplied).

These recent state efforts suggest that the EPA's unconstitutional encroachments on the states and their citizens will not prevail through the states' "own faults." Across the country, a storm is rising in opposition to federal overreach. This opposition will succeed if states continue to once again "act like" states, taking it upon themselves to reclaim our Constitution and, with it, our liberties.

Thomas K. Lindsay directs the Centers for Tenth Amendment Action and Higher Education at the Texas Public Policy Foundation and is editor of SeeThruEdu.com. He was deputy chairman of the National Endowment for the Humanities under George W. Bush.