Sen. Jon Tester of Montana was similarly unenthusiastic about ending federal marijuana penalties. Legalization would “cause more problems than it solves,” Tester said.

Schumer can’t afford to lose a single vote on his side of the aisle in his legalization push, and that’s before an even tougher battle to win over Republicans who have little interest in working with Democrats. If Schumer can’t find a path to Senate passage this year, with a midterm election that’s historically not been kind to the president’s party, it could mean a long delay before pot is legal in the U.S. — even as 18 states have embraced full legalization.

As he seeks reelection in a state that recently legalized recreational marijuana, Schumer is working hard on the issue. He’s developing legislation with Sens. Ron Wyden (D-Ore.) and Cory Booker (D-N.J.) that most cannabis policy watchers speculate will build on a far-reaching marijuana legalization bill passed by the House on mostly party lines last year.

Schumer repeated that vow in a Senate floor speech on Tuesday as he lauded the pro-weed day of “4/20,” a tradition since the 1970s.

“Hopefully the next time this unofficial holiday 4/20 rolls around, our country will have made progress in addressing the massive over-criminalization of marijuana in a meaningful and comprehensive way,” Schumer said.

Marijuana legalization has spread rapidly across the country, with more than 40 percent of Americans now living in states that have embraced full legalization. Polling shows that nearly 70 percent of the public supports cannabis legalization, double the level of support two decades ago.

But as it stands on Capitol Hill, Schumer does not have enough votes from his own party to pass cannabis reform, let alone the 10 or more Republicans necessary to reach 60 — the threshold needed to bypass a likely filibuster. If a cannabis vote was held in the Senate tomorrow, the bill would certainly fail.

In addition to Shaheen and Tester saying they would not support removing federal marijuana penalties, Sens. Joe Manchin (D-W.Va.), Bob Casey (D-Pa.) and Mark Kelly (D-Ariz.) said they are undecided on legalization.

“Everything seems like it’s moving in that direction,” said Manchin, whose state has legalized medical marijuana but not recreational use. “But right now, we’re not there.”

A Schumer spokesperson referred to his previous comments to POLITICO that indicated he was open to revising his comprehensive approach in order to win more votes.

Moderate Republicans are hardly leaping to fill the shoes of Shaheen, Tester or any other Democrat. Even those from states with legal recreational marijuana — such as Republican Sens. Mike Rounds of South Dakota, Steve Daines of Montana and Dan Sullivan of Alaska — are against or undecided on removing marijuana entirely from the Controlled Substances Act.

“I think this is a terrible public policy,” Rounds said soon after his state legalized cannabis in November. “I have not changed my position on it.”

Rounds is out of step with voters in his state. South Dakotans approved a measure to legalize adult-use cannabis 54 to 45 percent in November.

The House has already taken steps to reflect the emerging consensus on legalization: In December, it passed a bill to remove federal penalties on cannabis. But the Senate is yet to even consider a similar bill in committee.

“Despite public polling on this issue, and the issue’s popularity, it doesn’t seem to be having an effect on a sufficient number of senators,” said John Hudak, an expert on cannabis at The Brookings Institution. “I think they should be less scared of this issue. But ultimately, they’re not.”

Win-win situation

A party holding political power rarely gains by failing to follow through on a promise. But in the case of cannabis, which has broad support among both Democratic and Republican voters, legalization supporters argue that a failure this year could work to Democrats’ advantage. That’s because Schumer and other progressives could then wield the issue as a cudgel against the GOP in next year’s midterms.

“A failure serves as a motivator for 2022, saying ‘We need more Democrats,’” Hudak pointed out. “That can be an effective fundraising message for [Schumer].”

Industry officials argue the issue is a political winner regardless of whether Congress currently has the votes for a major overhaul of federal marijuana policies.

“I think there is room for ... being more progressive with it, without a loss being seen as a political negative in the same way that maybe some other” issues might be, said Charlie Bachtell, CEO of Cresco Labs, a major cannabis company with operations in multiple states, as well as chair of the National Cannabis Roundtable, a leading industry group. “I think it would be more of an issue for [Schumer] if he doesn’t bring it [up].”

Libertarian support?

Schumer could find unexpected legalization support from the GOP, but may need to make some compromises on the bill in order to do so. Libertarians like Republican Sens. Cynthia Lummis of Wyoming and Rand Paul of Kentucky signaled openness to descheduling marijuana under the Controlled Substances Act, but Republicans have balked at tax and racial equity provisions in legislation like the MORE Act in the previous Congress.

“I’m not a big fan of having a federal excise tax and adding criminal penalties to regulations,” Paul said.

Removing social equity funding or provisions to expunge criminal records could lure additional Republicans to a cannabis reform bill. But those changes could alienate Democrats — especially progressives who will not pass a cannabis bill without criminal justice reform language.

“The decriminalization of possession is something I’ve already supported, but legalizing requires more work on my end, on the science of it,” said Casey, whose state has legalized medical but not recreational marijuana. Casey and Sen. Joni Ernst (R-Iowa) introduced a bill last Congress to automatically seal federal convictions and arrests for simple drug possession.

“Whether or not … this comprehensive reform bill has a likelihood of success or not [depends on] how they tackle those gray areas,” Bachtell said.

Ultimately, neither party has reached consensus on a unifying political strategy when it comes to cannabis reform. Trying to find 50 votes for a comprehensive bill in this Senate — let alone 60 — will be exceedingly difficult.

Alternate pathways

Schumer has already found creative ways in the 117th Congress to get Democratic priorities over the finish line. The so-called budget reconciliation process requires only a simple majority vote but demands that any bill it’s used for have a substantive budgetary effect.

A federal excise tax on marijuana, for example, could qualify for the process, though tackling a narrow change like that through the budget would require going around Republicans in order to circumvent a filibuster. It’s far from clear that that approach could win the support it needs from all 50 Senate Democratic Caucus members.

“The challenge for Schumer … is that someone like Manchin or someone like Shaheen is going to look at this issue and say, this has nothing to do with the larger bill,” Hudak said. “Could something like the MORE Act be included in reconciliation? Yes. Is it politically feasible for it to get included in any reconciliation? The answer is probably no.”

One other pathway exists: legislation that would make it easier for marijuana companies to access banking, known as the SAFE Banking Act. Tester and Sullivan told POLITICO their focus is on passing that banking measure, which has much stronger support in both parties. Bachtell suggested a middle-ground route between the banking bill and comprehensive reform to get more Democrats on board.

“Something in the middle there is where they’re going to focus their efforts,” Bachtell said, in a bid to “get something done before priorities shift to [the] midterm election cycle.”