Wednesday night’s Democratic debate featured one moment that made a few audience members gasp: when Cory Booker delivered a stinging one-liner at Joe Biden over the issue of marijuana legalization. Underneath it, however, was an interesting policy disagreement that shows how the Democratic Party has moved significantly to the left even as it still trails behind public opinion.

Booker brought it up himself; in the context of a question about racial equality, he looked over at Biden and said, “I have a lot of respect for the vice president — he swore me into my office, he’s a hero. This week, I hear him literally say that I don’t think we should legalize marijuana. I thought you might have been high when you said it.”

Booker was referring to comments Biden made earlier in the week, when the former vice president said “there’s not nearly been enough evidence that has been acquired as to whether or not it is a gateway drug.” He was immediately ridiculed for the “gateway drug” argument, a staple of ’80s-era “Just Say No” campaigns that tried to convince kids that if you took a puff on a joint, within a few days you’d be shooting up heroin.

Far less attention was paid to Biden’s actual position on marijuana, which is that it should be moved from Schedule I to Schedule II (allowing more research on it than is currently permitted) and decriminalized at the federal level to let states decide whether to legalize it for recreational use. He would also expunge all convictions for possession.

This is a position more conservative than that taken by his opponents, especially Booker, who is the principal sponsor of the Marijuana Justice Act and other legislation that would not only legalize marijuana but would also seek to address the consequences of the War on Drugs. (Almost all the other senators running for president have co-sponsored Booker’s bill.) But it’s still much more liberal than where the Democratic Party as a whole was just a few years ago.

There’s an interesting parallel with how the health-care debate played out. Joe Biden became the representative of the “moderate” Democratic view on health care, which is that instead of Medicare-for-all we should have a comprehensive public option. As I argued when Biden released his plan, this represents a striking move to the left, because the moderate position is now one that was considered far too radically liberal for Congress when President Barack Obama and his vice president were pushing to get the Affordable Care Act passed.

The situation on marijuana isn’t exactly the same, but it’s not far off. Biden was a legendary tough-on-crime drug warrior in the Senate, but now he’s taking a position that is far more permissive than that of the Obama administration was.

Obama himself regularly expressed the opinion that the nation’s drug laws should be far less restrictive, but he would also be quick to note the restraints on what he could do about it unilaterally without an act of Congress, one that was not in the offing. His Justice Department had a kind of limited hands-off policy with regard to states that had passed their own legalization laws, a policy that was rescinded when President Trump took office. (“Good people don’t smoke marijuana,” said Trump’s first attorney general.) But nobody would say Obama put a lot of energy into trying to change the country’s marijuana laws.

So now Joe Biden argues that we should go further toward legalization than Obama did — and he’s taking the moderate position.

But that’s still well behind where the public is. According to the most recent data from the Pew Research Center, a whopping 67 percent of the American public thinks that marijuana should be legalized, a number that has more than doubled in the past two decades. With the exception of the Silent Generation (people born before the end of World War II), a majority of just about every demographic group supports legalization. Not only do 78 percent of Democrats support it, but 55 percent of Republicans do, as well. Republicans!

There are many reasons, perhaps most importantly the dying off of older generations that believed cannabis was some kind of evil weed that could turn ordinary people into violent lunatics with a single lungful. The fact that 33 states and D.C. have passed either medical marijuana or legalization for recreational use without the sky falling down has probably also convinced a lot of people that there isn’t that much to fear from the drug being legal — or at the very least, that legalization brings with it fewer harms than prohibition.

When Booker went after him, Biden looked a little surprised. Perhaps it was the zinger about him being high, or perhaps it was the fact that he figured he’d get some credit among Democrats for moving left of where he and the party had been in the past. It seldom works that way, however; whatever the party thinks now will always be considered the only acceptable position.

Biden may have moved left, but as he found out, he hasn’t gone far or fast enough.

Read more: