Key Democrats, including Senate Majority Leader Charles E. Schumer (D-N.Y.), said Tuesday they would work to repeal federal prohibitions on marijuana cultivation and use, vowing to make progress on an issue that has growing public support but still faces sharp objections from most Republicans.

Speaking on April 20 — a folk holiday for marijuana enthusiasts — Schumer said on the Senate floor that he planned to draft and advance Senate legislation “not only to end the federal prohibition on marijuana, but to ensure restorative justice, protect public health, and implement responsible taxes and regulations.”

“It makes no sense. It’s time for change. I believe the time has come to end the federal prohibition on marijuana in this country,” he said, adding that strict federal penalties for cannabis have disproportionately hurt people of color who serve long jail sentences over possession of the drug and then struggle to obtain jobs because of their criminal records.

While Schumer referred to the planned legislation as “legalization,” it is unlikely to have any effect on the myriad state laws that restrict cannabis. But it could very well undo many federal laws on the subject, including reclassifying or removing marijuana from the federal schedule of controlled substances, which classifies it as a dangerous drug with no legitimate medicinal use.

That classification is now in conflict with laws in three dozen states that allow the medical use of cannabis, as well as 17 states, plus D.C., that have legalized recreational use by adults. It is also in growing conflict with the wishes of voters, who increasingly favor some degree of liberalization.

According to a recent Pew Research poll, 91 percent of Americans think marijuana should be legal in some form, with 60 percent supporting its use both recreationally and medicinally and 31 percent saying it should be used only medicinally.

The House voted in December to pave the way for the federal decriminalization of marijuana sales, including descheduling it as a drug and providing for its regulation and taxation. This week, the House is expected to pass a more limited bill that would allow U.S. banks and financial services companies to do business with cannabis-related enterprises.

The conflicts between the increasingly loose state laws and the federal enforcement regime have sparked calls for change across the ideological spectrum, but most Republican leaders have resisted any call for liberalization.

“What’s he been smoking?” quipped Sen. John Cornyn (R-Tex.), a senior member of the Senate Judiciary Committee, when told of Schumer’s wishes.

“I don’t see any significant Republican support for decriminalizing,” said Sen. Roy Blunt of Missouri, a member of the Senate Republican leadership.

Senate Minority Leader Mitch McConnell (R-Ky.) has supported loosening federal laws to allow for research into and the cultivation of industrial hemp, a nonintoxicating relative of recreational cannabis. But he has stopped well short of endorsing any further measures.

Even Republican senators who said they support states that are choosing to adjust their marijuana laws said they did not think it was necessary for the federal government to follow suit.

“That’s going to cascade through the states, just like it has been, and I think that’s the best way to do it,” said Sen. Mike Braun (R-Ind.). “In terms of doing anything federally, I don’t think there’s any need for that right now.”

But Democrats increasingly think they are on the right side of the politics of the issue by pushing for liberalization, with fewer qualms than ever among moderates. Only six of 232 House Democrats voted against the decriminalization bill in December.

Rep. Hakeem Jeffries (D-N.Y.), a lead sponsor of the bill and the Democratic caucus chairman, called Schumer’s vow to pursue legislation in the Senate “super encouraging.” But it remains unclear what bill the Senate might be able to pass, with Democrats holding the majority in a 50-50 chamber only because of Vice President Harris’s tiebreaking vote.

“At the end of the day, I think we’re going to be able to get something done, particularly because we’ve got affirmative visionary leadership from Chuck Schumer,” Jeffries said.

Schumer said Tuesday that Sens. Ron Wyden (D-Ore.) and Cory Booker (D-N.Y.) would lead efforts to write the bill. Wyden, chairman of the powerful Senate Finance Committee, introduced legislation that would deschedule, tax and regulate marijuana while also removing federal barriers to cannabis-related firms that do business in states where laws have been loosened.

White House press secretary Jen Psaki said President Biden supports “decriminalizing” marijuana, expunging criminal records and legalizing medicinal marijuana, but would leave legalization for recreational use to the states. She said Biden did not support completely descheduling marijuana as a dangerous drug but rather reclassifying it to allow for more research.

“We understand the movement that’s happening toward” legalization, she said. “He wants to decriminalize, but again, he’ll look at the research of the positive and negative impacts.”

While five Republicans supported the December House bill, Schumer did not mention any bipartisan talks in the Senate — which would be a prerequisite for passage so long as the 60-vote threshold for overcoming a filibuster remains in place.

Sen. Rand Paul (R-Ky.), who has libertarian views on drug laws, said he had not heard from Schumer or any other Democrat about collaborating on a potentially bipartisan bill.

“He needs to call me,” Paul said Tuesday. “I’d be the most likely to be sympathetic. . . . If they think they want to pass something with Republicans, they ought to try, but so far I haven’t had any outreach.”

Another option for Democrats could be to try to use the process known as budget reconciliation to pass marijuana laws with a 51-vote majority. But that process is reserved for provisions with a discrete impact on the federal budget, and a new regime of regulation might not pass muster with the Senate parliamentarian who rules on such issues, some aides said.

Sen. Bernie Sanders (I-Vt.), who oversees the reconciliation process as Budget Committee chairman, said he was open to trying to include cannabis measures in a future reconciliation bill, but “there are a whole lot of questions out there.”

Legalizing and taxing marijuana would undoubtedly have budgetary impact, he said, but “it’s a little bit more complicated.”