Cory Booker launched his 2020 Democratic presidential bid on the first day of Black History Month in 2019, with a promise to crusade for a “criminal justice system [that] keeps us safe, instead of shuffling more children into cages and coffins.”

Politicians generally pack their announcement speeches with platitudes that are far more ambitious than their candidacies. They begin with poetry, yet more often than not end up speaking the compromised language of our all-too-predictable politics.

But Booker kept his audacious promise throughout a campaign that ended Monday, on the eve of a debate he was turned away from because of the Democratic National Committee’s ill-conceived rules.

The senator from New Jersey campaigned as a passionate and consistent advocate for bold and long-overdue reform. He kept coming back to the issue, going deeper, pushing harder. He linked it to the most fundamental challenges facing American society, declaring in the September Democratic presidential debate in Houston, “We have systemic racism that is eroding our nation from health care to the criminal justice system. And it’s nice to go back to slavery, but dear God, we have a criminal justice system that is so racially biased, we have more African Americans under criminal supervision today than all the slaves in 1850.”

In particular, Booker ran against the devastatingly destructive “war on drugs” that top Democrats once embraced as enthusiastically as top Republicans. Though he regularly emphasized unity, and had kind words for his fellow contenders, on this issue the senator cut the front-runner no slack. After former vice president Joe Biden expressed skepticism about legalizing marijuana—employing 1980s rhetoric about the need for more research on whether smoking weed is a “gateway” to more serious drug use—Booker delivered one of the most memorable lines of the 2020 campaign.

“I have a lot respect for the vice president—he swore me into my office, he’s a hero,” Booker said as the two men faced off on a debate stage in November. Then, noting that “this week I hear him literally say that [he doesn’t] think we should legalize marijuana,” Booker turned to Biden and announced: “I thought you might have been high when you said it.”

The line got a laugh.

But Booker, the sponsor of the federal Marijuana Justice Act (a measure that “seeks to reverse decades of failed drug policy that has disproportionately impacted low-income communities and communities of color”) was serious about delivering this message.

“[Marijuana] in our country is already legal for privileged people,” said the senator, who explained that “the war on drugs has been a war on black and brown people.”

As the applause from the crowd grew, Booker continued. “With more African-Americans under criminal supervision in America than all the slaves since 1850, do not roll up into communities and [fail to] talk directly to issues that are going to relate to the liberation of children, because there are people in Congress right now that admit to smoking marijuana, while there are people—our kids are in jail right now for those drug crimes.”

Concluding one of the last statements he made from a Democratic debate stage, Booker said that the party needs “somebody authentically” committed to addressing the issue as its 2020 nominee, because “these are the kind of issues that mean a lot to our community.”

He was right. But he will not be the nominee.

The remaining Democratic contenders have had some nice things to say about Booker and his campaign. Rightly so. He deserves credit for having mounting an honorable, upbeat bid that was all about ideas and relentlessly focused on the work of defeating Donald Trump. But the candidates who are still in the running—several of whom (including Vermont Senator Bernie Sanders and Massachusetts Senator Elizabeth Warren) have worked with Booker on marijuana law reform initiatives—should do more. If they really want to recognize and respect Cory Booker’s many contributions to the 2020 race, they can begin by fully and explicitly embracing his crusade on behalf of criminal justice reform—and his essential critique of the drug war.