On Friday, for the first time in history, a house of Congress passed a bill decriminalizing marijuana at the federal level. Which is without doubt a landmark event — but don’t celebrate too much. Congress is still lagging behind both the states and the public on this issue.

The bill, the Marijuana Opportunity Reinvestment and Expungement Act, starts by removing cannabis from the federal drug scheduling system, which classifies it as Schedule 1, meaning it has “no currently accepted medical use and a high potential for abuse,” along with heroin and LSD.

The act also begins the process of expunging federal marijuana convictions and removes penalties for those with such convictions, including the denial of student loans and other federal benefits.

Although there is a companion bill in the Senate — sponsored by Vice President-elect Kamala D. Harris, among others — there is no chance it will get a vote there, especially as long as the chamber is controlled by Republicans. (Only five Republicans in the House voted in favor of the bill.)

That’s despite the fact that legalization is barely controversial anymore.

The change in public opinion on this issue has been remarkable; perhaps only on gay rights have we seen this kind of wholesale shift in the public’s thinking in recent years. Look at how steadily support has increased in Gallup polls:

In 2000, 31 percent of Americans thought “the use of marijuana should be made legal.” By 2010, the number was 46 percent. And in October 2020, it was 68 percent. Majorities in every age and income group now support legalization; even 48 percent of Republicans support it.

There are a number of factors contributing to this change, all interacting with each other. The first is generational replacement: Very few of those older than baby boomers had any exposure to cannabis in their youth. That means that not only haven’t they tried it themselves (and survived), but they also didn’t have friends and family who used it and so were more likely to believe propaganda about the drug’s effects, like this terrifying 1952 episode of “Dragnet” in which Los Angeles is overrun with senseless violence and mayhem committed by teens in the grip of the vile weed.

As the older generations die off and are replaced by those who grew up with very different ideas, public opinion shifts. Add in popular culture and change in state laws, and you have an environment in which prohibition advocates inevitably find support for their position shrinking more and more.

You can see it most clearly at the state level. This November, voters passed laws legalizing marijuana in New Jersey, Arizona, South Dakota and Montana; in Mississippi, a medical marijuana initiative passed. The latter three states were all won easily by President Trump. There are now 15 states (plus D.C.) that have approved recreational use, and 36 states that allow medical use.

What about the incoming president? Joe Biden — who, by the time the kids gathered at Woodstock, was already a parent working as a lawyer and planning his political career — has displayed a reticence to go too far on the issue of cannabis. But, as in many other areas, he has been pulled left by the evolution of the public and his party.

During the campaign, he supported the kind of decriminalization embodied in the More Act, even as many of his opponents advocated outright legalization (you may remember this amusing exchange between him and New Jersey Sen. Cory Booker, an advocate of legalization, during a primary debate). And while Harris has acknowledged getting high in her youth (“I did inhale”), nobody that I know of has even bothered to ask Biden whether he ever has, because the answer is so obvious.

It’s not clear just how far Biden’s administration will go, but we’ll probably look back and say that Jeff Sessions was the last attorney general who made going after pot-smoking hippies a centerpiece of his agenda.

As often happens in areas where public opinion has shifted, politicians lag behind their constituents and stick with what they consider a safe position. For now, the safe position for Democrats is to support decriminalization at a minimum, while for Republicans it’s to oppose almost any change in the country’s drug laws.

That’s where Republicans are now, but sooner or later, even the GOP will probably come around. At the very least, it won’t be a fight they have any interest in waging.

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