In 1787 the Constitutional Convention produced a charter for a federal government of limited, delegated and enumerated powers–only those powers specifically stipulated. One power enumerated in 1787 is the power to “regulate Commerce… among the several States.”

Exactly 150 years later, at the height of the New Deal struggle to expand the scope of federal power vastly by saying it is exercised to regulate interstate commerce, the Supreme Court, in what became known as “the constitutional revolution of 1937,” got out of the federal government’s way. The court essentially said it would no longer scrutinize congressional claims that almost any activity can substantially affect interstate commerce, and therefore Congress can regulate almost anything. The court thereby allowed the federal government to slip one of the leashes that could keep it a limited government.

In 1995, for the first time since 1935, the court struck down a law as congressional overreaching with the Commerce Clause. That law made it a crime to have a gun near a school. The court said that the law erroneously presumed that the Commerce Clause effectively grants Congress general police power over the nation. The four dissenters argued that a gun near a school might produce violence which might raise insurance costs, and might make individuals reluctant to travel, and might injure national productivity by harming the learning environment. The majority said that by such reasoning Congress could regulate child rearing because it is an activity that has a substantial effect on interstate commerce.

Now, to last week, when the court partially undid what Congress did in 1994, when it passed the Violence Against Women Act. One provision of the VAWA gave women who are victims of violence “motivated by gender” a right to sue their attackers in federal courts. In 1994 a Virginia Tech freshman said she was raped in a dormitory by two members of the football team. Dissatisfied with Virginia Tech’s response (which was to find only one man guilty, and only of “using abusive language,” and to allow him to continue playing football), the victim sought help not under Virginia law but under the VAWA provision. Last week the court held that provision unconstitutional because the Founders “reposed in the States… the suppression of violent crime and vindication of its victims.”

The decision was even more portentous than the 1995 decision concerning the 1990 gun law. Congress had made only a perfunctory attempt to establish that guns near schools have a substantial effect on interstate commerce. In contrast, when passing the VAWA Congress held considerable hearings purporting to show how fear of violence would give women inhibitions about traveling, or working at night, and about how much violence against women costs the economy. However, Chief Justice Rehnquist, joined by Justices O’Connor, Scalia, Kennedy and Thomas, dismissed this as not germane: “Gender-motivated crimes of violence are not, in any sense of the phrase, economic activity.”

Well, now. If the Commerce Clause can justify congressional regulation only of a clearly economic activity, what then of some environmental laws, such as the Endangered Species Act? David Savage of the Los Angeles Times writes: “Some critics have suggested Congress has no power to protect a threatened animal or plant that lives in only one state and has no effect on interstate commerce.”

And the constitutional reasoning that invalidated the VAWA is pertinent to an issue of the current political season. The reasoning should inhibit Congress from passing “hate crimes” legislation. States are free to pass such laws, which many politicians use as moral pork. Such laws often are indignation gestures: politicians pass them in order to strike poses that please particular constituencies by saying that some crime victims (women, gays, minorities) are especially important. Still, such laws, wise or foolish, are within a state’s power. By the logic of the court last week, federal hate-crimes legislation intrudes on a responsibility that Rehnquist says is “reposed in the States.” But the potential sweep of last week’s ruling extends far beyond federal crime policy. Prof. Glenn H. Reynolds of the University of Tennessee College of Law suggests that the ruling, which proved that the 1995 ruling was not a single eccentric departure from post-1937 jurisprudence, puts lower courts on notice not to continue ignoring the highest court’s determination to breathe life back into the Founders’ doctrine of enumerated powers.

There will be huge consequences if last week’s ruling signals judicial intolerance of the sophistical argument that any activity is economic, and therefore subject to congressional regulation, if the activity, multiplied by thousands of instances, could conceivably have some economic consequence. Reynolds, peering far down a possible road, sees diminished interest in campaign-finance reform: there will be less money in politics because there will be less need to influence a federal government limited to its “few and defined” powers (the words of the father of the Constitution, James Madison). Reynolds may be allowing his Madisonian wishes to be the father of his somewhat extravagant thought.

Be that as it may, last week’s ruling underscores a potentially huge stake of this presidential election. The next president might nominate at least three Supreme Court justices. Any president who serves two terms could appoint approximately half the federal judiciary. And questions of the constitutionally correct balance between the powers of the federal government and those of the states are always important and never closed. So the next president probably will have the power to accelerate, or halt, what the court has begun–a jurisprudential counterrevolution in defense of federalism.