Oh what a tangled web we weave when from the text we take our leave—or so it seems after reading the op-ed by David Rivkin and Elizabeth Foley in today’s Wall Street Journal, “Federal Antidrug Law Goes Up in Smoke.” Not that they’re entirely wrong, mind you, in their defense of the attorneys general of Nebraska and Oklahoma, who are suing to have the Supreme Court declare Colorado’s law legalizing marijuana unconstitutional. In fact, they’re relying simply on modern “constitutional law,” which has succeeded in this case in bringing a tangle of constitutional principles and powers to a fine boil.

Start with First Principles. In a radical fit some years ago I argued not only that Congress had no authority to wage a war on drugs under its power to regulate interstate commerce—its rationale for doing so today—but that it had a duty under the Fourteenth Amendment to block states from waging such a war. Since Congress’s commerce power was granted mainly to enable it to ensure free commerce among the states, especially by checking the kinds of state interference that had arisen under the Articles of Confederation, not only did Congress have no power to interfere with interstate commerce in “recreational” goods like tobacco, alcohol, and marijuana, but it had an affirmative power to check state interference with such commerce, as the Court held in 1824 in its first great Commerce Clause case, Gibbons v. Ogden. Moreover, since the general police power held by states was meant mainly to protect rights, not only could it not be employed to interfere with economic and personal liberty, but once the Fourteenth Amendment enabled individuals to seek federal protection against state violations of their rights, Congress had authority under section 5 of the amendment to afford that protection.

That’s not the law today, of course. Far from reading the Commerce Clause as empowering Congress to make commerce among the states “regular,” the Court read it in 1942 in the infamous case of Wickard v. Filburn as allowing Congress to prohibit a farmer from growing wheat in excess of the amount allotted by law even though the wheat never entered any stream of commerce—on the theory that his doing so, in the aggregate, “affected” interstate commerce, the same theory the Court used in 2005 in Gonzales v. Raich when it held that Congress could criminalize the medicinal use of home-grown marijuana, which California law allowed. Throw in the Supremacy Clause, which makes federal law supreme over conflicting state law, the Take Care Clause, which requires the president to see that the laws be faithfully executed, and add principles concerning federalism and individual liberty, and we have the fine constitutional brew that Rivkin and Foley are stirring.

Nebraska and Oklahoma complain that a significant influx of marijuana purchased in Colorado is increasing their law-enforcement costs. Hence their suit, arguing that “the Constitution and the federal anti-drug laws do not permit the development of a patchwork of state and local pro-drug policies and licensed-distribution schemes throughout the country which conflict with federal laws.” To conservatives complaining that the two states are “fair-weather federalists,” Rivkin and Foley answer that they should be directing their fire at President Obama, whose “now-signature response to disfavored laws” is to issue a memo directing federal law-enforcement officials, in this case, to ignore the federal ban in states that have liberalized their marijuana laws. The law is clear, they believe. Federal law trumps conflicting state law. And under Arizona v. United States (2012), even when the president won’t enforce that law, states “may not pursue policies that undermine federal law,” as policies in Colorado and three other states allegedly now do.

But do they? What precisely is Colorado doing that undermines federal law? Rivkin and Foley cite Colorado’s attorney general as saying that “his state is ‘becoming a major exporter of marijuana.’” He was doubtless speaking loosely there. After all, the state isn’t exporting marijuana. In essence, what the state has done is legalize the sale and use of marijuana—as if it had never made it illegal in the first place. Nothing requires a state to make marijuana illegal. Nor is the state doing anything to prohibit federal enforcement of federal prohibitions. It’s doubtful, therefore, that there is any conflict here.

Yet the issues and implications drawn together here are far reaching. Obama’s “law-by-memo” practices have arisen well beyond the war on drugs—with Obamacare, with same-sex marriage, with immigration, and more, all of which is now in litigation. And Rivkin and Foley are not oblivious to how this tangled web arose. “Whatever one thinks about Raich,” they write (or Wickard, one might add). And they note that “the Controlled Substances Act can be amended or repealed,” or the attorney general “could use his authority under the CSA to remove marijuana from Schedule I.” The heart of the problem remains, however, with the expansion of Congress’s commerce power beyond its intended bounds. When that happens, entanglement is inevitable and liberty suffers.