There are good arguments for and against “safe-injection” sites — such as the one that opened in East Harlem in December — allowing addicts to inject street drugs under watchful eyes. They offer the opportunity to reverse overdoses and provide sanitary conditions. But neighbors fear that addicts will gather on street corners and bring crime and disorder. There’s one big reason, however, such facilities should not be permitted: They are illegal under federal law.

But that’s not stopping President Joe Biden’s Justice Department from indicating it will work to regulate, not oppose, such “overdose prevention” centers. “The position is a drastic change from its stance in the Trump administration, when prosecutors fought vigorously against a plan to open a safe consumption site in Philadelphia,” as the Associated Press puts it. That effort succeeded in court because federal law, inspired by the 1980s crack house epidemic, bans operation of a site for using drugs. Yet the Biden Justice Department says it’s pondering “appropriate guardrails,” not legal opposition.

As worrisome as this is for those concerned about encouraging drug use, the new Justice position is about much more than safe-injection sites, already operating in New York and clandestinely in San Francisco’s Tenderloin district.

Recall Biden issued a moratorium on deportations his first day in office, and his Department of Homeland Security secretary, Alejandro Mayorkas, instructed border agents to “first examine and consider the impact of where actions might possibly take place, their effect on people and broader societal interests” before arresting illegal immigrants.

That should be the job of Congress, not an executive branch sworn to uphold the law.

Team Biden is broadly signaling its support for a movement best described as “law non-enforcement” or, in the federal context, “executive non-action.”

It’s the approach Manhattan District Attorney Alvin Bragg broadcast in his January memo proclaiming he won’t prosecute so-called minor crimes — such as the turnstile-jumping that has long led police to gun-toting criminals. Bragg has stepped back from his most extreme positions, but time will tell what his record will be.

Bragg is part of a national non-enforcement movement among district attorneys including Chesa Boudin in crime-ridden San Francisco, Philadelphia’s Larry Krassner and Boston’s Rachael Rollins, who, as part of her focus on reducing “racial disparities,” pledged not to prosecute such “low-level crimes” as trespassing, drug possession and resisting arrest. Biden, his professed opposition to police defunding notwithstanding, nominated Rollins for Massachusetts US attorney. She was confirmed, though as Sen. Tom Cotton said, she’s a “prosecutor in name only.”

There’s a key difference between Biden’s non-enforcement of the law and, say, New York’s “bail reform” rules ensuring those charged with crimes are not held before trial and California raising the value of stolen goods required for a misdemeanor charge, which set off a shoplifting wave. These are bad laws — but they were passed by, in the first case, a democratically elected, if misguided, Legislature and, in the second, a referendum. They can be repealed.

But prosecutors, not to mention the federal Justice Department, are by definition meant to enforce the law — and indeed take an oath to support the federal and state constitutions. All prosecutors can, and should, operate with some discretion. But that’s quite different from declaring entire classes of crime are to be overlooked. That’s why San Francisco’s Boudin is facing a recall election — an option not available in New York and many other states.

Changes in the criminal code should be made by legislation, not prosecutorial caprice motivated by ideology. If proponents of safe-injection sites had the courage of their convictions, they would petition Congress to make such facilities legal.

The Justice Department, bound to “protect and defend” the country, should enforce the law until and unless it is changed. By throwing his lot in with progressive prosecutors, Joe Biden is setting a dangerous precedent.

Howard Husock is an American Enterprise Institute senior fellow.