The Supreme Court on Thursday that not even illicit drug use can alter the fact that the Second Amendment makes firearm ownership a fundamental right.

At least as importantly, it reaffirmed the importance of the due process of law, including the crucial principle that an alleged criminal offense cannot be used to turn otherwise-legal behavior on a completely unrelated front into a crime of its own.

Put another way, there’s no such thing as guilt by osmosis.

The main thrust of the decision in had been expected due to the tenor of various justices’ comments during oral argument on March 2. The case, the government’s appeal of a decision of the U.S. Fifth Circuit Court of Appeal based in New Orleans, involved a man named Ali Hemani who smoked marijuana several days a week and also owned a handgun, safely secured at home.

The government, relying on federal law, 18 U.S.C. § 922(g)(3), said that because Hemani smokes pot, it is illegal for Hemani even to own a gun — even though the pot use and the gun ownership are otherwise wholly unrelated, and even though Hemani had no prior criminal record and had not even been charged with a criminal offense for the marijuana use itself. The Fifth Circuit disagreed with the government, and now the Supreme Court has affirmed that decision.

I’ve been writing on this in numerous columns . I am an avid opponent of legalizing marijuana (I’ve never smoked it, not even once), and I haven’t even fired a gun in decades, so I have no personal ax to grind here — but the principles involved should be of interest to everyone who cares about constitutional liberty.

The first eight amendments to the Constitution (along with the thirteenth through fifteenth) protect rights that are recognized as essential to civil society and which should be seen as naturally belonging to all humankind, rather than being merely granted by a benevolent government. This is no less true for Second Amendment weapons rights than for First Amendment religious or speech rights.

In hundreds of cases, the Supreme Court has explained that government can restrict a fundamental right only after “strict scrutiny,” which means the restriction must be “narrowly tailored” and be the “least restrictive means” of achieving a “compelling government interest.”

Unless and until an actual criminal conviction (or perhaps a formal medical diagnosis, in accordance with some law or other) carries with it a concomitant restriction on future firearm ownership, there is absolutely no compelling government interest, narrowly tailored, that can allow the denial of the fundamental Second Amendment right.

If the gun is not used in a crime, and if simple marijuana use is at most a misdemeanor, and if the gun isn’t handled or brandished while under the influence, then the government has no legitimate authority to make gun ownership illegal.

Such has been my argument for years — ever since I analyzed a case in which an Alabama public official was convicted for illegal gun ownership because he had a handgun in his bedroom in Mobile while he smoked a joint on a Florida beach 67 miles away. Yes, that conviction was absurd, and so was Hemani’s in this case.

On Thursday, the court agreed, without a single dissent.

In the main opinion, Justice Neil Gorsuch noted that by the government’s flawed argument (in favor of prosecution), it doesn’t even matter “how much [or little] marijuana Hemani uses or what effect it has on him. It makes no difference either if he keeps a firearm only in his home for self-defense, never misuses a gun while intoxicated, and never poses a danger to himself or others as a result of his marijuana use. The only thing the government must show, it says, is that an individual like Mr. Hemani regularly uses any amount of any controlled substance …. But the government’s [argument] fails under every measure it asks us to consider.”

A criminal conviction should be imposed for the crime actually committed. Otherwise, our liberty writ large is at the whim of rogue prosecutors or of selective, even politically targeted enforcement by officers on power trips. The protections against such abusive practices are particularly compelling when an explicit constitutional right is at issue.

No matter how much I or anyone else might object to marijuana, the Supreme Court, like the Fifth Circuit in New Orleans, got this one right. We can’t let our rights go up in smoke.

Email Quin Hillyer atquin.hillyer@theadvocate.com