Has there even been a point of time in which so many public controversies rest on a single, abstract principle of constitutional government? I can’t think of one.

The principle in question is the separation of powers. Here are only some of its recent political manifestations:

• The U.S. Supreme Court has just blocked President Joe Biden’s attempt to transfer hundreds of billions of dollars in debt from student borrowers to federal taxpayers. The federal constitution gives Congress the power of the purse, not the president, and the statute Biden cited as giving him sweeping authority to transfer debt did no such thing.

• The Supreme Court also struck down the racial preferences used by the University of North Carolina at Chapel Hill and other highly selective institutions to discriminate against white and Asian students. In her dissent, Justice Ketanji Brown Jackson argued that if her colleagues believe “preventing consideration of race will end racism,” their intention will “be in vain.” But as Chief Justice John Roberts wrote in the majority decision, the judiciary isn’t authorized to pursue policy intentions of any kind. Its job is to decide whether specific acts are lawful. Racial discrimination isn’t. If you think there should be exceptions, your proper course is to rewrite the relevant federal statutes and constitutional provisions. Courts can do neither.

• In yet another decision with North Carolina connections, Moore v. Harper, the Supreme Court ruled that the constitutional language giving “state legislatures” the power to determine the time, place, and manner of federal elections does not exclude such legislative decisions from review by state courts.

As you may recall, the North Carolina Supreme Court intervened before the 2022 elections to strike down a congressional map drawn by the General Assembly. The state court, then composed mostly of Democrats, drew from general language in the state constitution about “free elections” and “equal protection” to invent a new rule against partisan gerrymandering. Then it authorized non-lawmakers to draw congressional districts for 2022. After the midterm elections, which produced a 5-2 GOP majority on the N.C. Supreme Court, this abuse of the separation of powers was (properly) reversed.

In the meantime, however, Speaker Tim Moore had appealed the case to the U.S. Supreme Court, arguing that under the federal constitution, state courts may exercise no legitimate oversight of congressional redistricting. Chief Justice Roberts disagreed, writing in this majority decision that Moore’s argument “does not account for the Framers’ understanding that when legislatures make laws, they are bound by the provisions of the very documents that give them life.” There is ample precedent for Roberts’ interpretation, such as a 1932 decision upholding the power of governors to veto congressional districts if that’s what their state constitutions permit. When the U.S. constitution refers to state legislatures, the court ruled, it does so in full knowledge that legislatures must act “in accordance with the method which the state has prescribed for legislative enactments.”

• Finally, on several occasions this session the North Carolina General Assembly has sought to strip the executive branch of significant influence over the enforcement of state laws and the administration of state agencies. As I’ve previously argued, you can be sympathetic to the legislature’s concerns without endorsing an unconstitutional remedy for them. Like the federal one, our state constitution specifically requires that the “legislative, executive, and supreme judicial powers of the state government shall be forever separate and distinct from each other.”

Why? Because checks and balances are essential to freedom and effective governance. The English philosopher John Locke argued in 1689 that in any “well-formed government,” the “legislative and executive powers are in distinct hands.” The man who coined the phrase “separation of powers,” Charles de Montesquieu, wrote in 1748 that “when the legislative and executive powers are united in the same person, or in the same body of magistrates, there can be no liberty.”

Process matters. That’s what we can learn from all of these disputes. Few lessons are more important.

John Hood is a John Locke Foundation board member. His latest books, Mountain Folk and Forest Folk, combine epic fantasy with early American history.