Roy Cooper spent his last few weeks as governor-elect of North Carolina attacking the state legislature for encroaching on the separation of powers, weakening the rule of law, subverting the will of the voters, and hurrying new policies through too quickly, without adequate discussion or consultation.

Roy Cooper then spent his initial few days as governor of North Carolina doing precisely what he’d accused the legislature of doing — and giving himself an unnecessary black eye.

Cooper’s first big mistake involves the same issue that severely damaged Barack Obama and his administration: the Affordable Care Act. The president came into office determined to expand government control of health care. He spurned contrary views and pushed through what he wanted. The public didn’t like it. Obamacare is the single-biggest reason why the Democratic Party is at its weakest point since the 1920s.

But progressives remain convinced that policy success and public approval are still just around the corner, and that Republicans won’t repeal and replace the ACA’s core policies of Medicaid expansion and government-run insurance exchanges. I don’t know if Cooper agrees with them or believes that he has no choice but to indulge the fantasies of his political base. I do know that the decision he announced on January 4 — to seek Medicaid expansion in North Carolina through executive action — is a colossal blunder.

Republican lawmakers have passed multiple laws to forbid Medicaid expansion without their approval. They get to do that. Medicaid expansion requires a state appropriation to match federal dollars, regardless of how that appropriation is funded (through general revenues or taxes on hospital bills). It is also a policy matter about which the legislative branch has constitutional authority, as House Speaker Tim Moore and Senate President Pro Tem Phil Berger have already informed the outgoing Obama administration.

I don’t see any way for the ensuing legal dispute to end well for the governor and Democrats. Either the North Carolina Supreme Court will confirm the obvious and deny Cooper the arbitrary power he claims to have to change state policy and appropriate state funds. Or, having just shifted from a 4-3 Republican majority to a 4-3 Democratic one, it will issue a dishonest opinion that will seem far partisan than anything the GOP-majority court ever did — while still not giving Cooper an actual win on Medicaid expansion.

How come? Because by the time such a decision is rendered, there won’t be an Obama administration to play with. The Trump administration is hardly likely to approve a Democratic governor’s scheme to circumvent the will of a Republican legislature. Moreover, the Republican Congress will likely reform Medicaid in ways that will make the dispute moot, either by forestalling expansion altogether or by rewriting the rules in such a way that state Republicans may decide to accept somewhat-broader eligibility rules in exchange for spending caps, flexibility, and private options.

By claiming unilateral authority to expand Medicaid, Gov. Cooper destroyed the political narrative he and his progressive enablers in the media had created after the 2016 election. Whatever you think of the Republican legislature’s decisions to reduce the number of political jobs Cooper can fill, strengthen the role of the state superintendent of public instruction, or combine the state’s ethics and elections boards, they don’t constitute a large-scale change in public policy. They don’t seek to obligate the state to spend billions of dollars without legislative approval.

The governor’s Medicaid gambit encroaches on the separation of powers, weakens the rule of law, and subverts the will of the voters who have elected a Republican president and Congress to take health care policy in a different direction. It also represents a major policy change hatched without adequate discussion or consultation, thus alienating even longtime advocates of Medicaid expansion such as the state hospital association who want bipartisan action.

I criticized Republicans in the legislature for acting too hastily during the December special session. Will the Left criticize Cooper for acting too hastily on his first week on the job? I won’t hold my breath.

John Hood is chairman of the John Locke Foundation and appears on the talk show “NC SPIN.” You can follow him @JohnHoodNC.