Senate Minority Leader Charles E. Schumer (D-N.Y.) (J. Scott Applewhite/AP)

It’s not just because it’s 4/20 — although that contributed to at least one important senator’s announcement that he has come around to the idea of decriminalizing marijuana.

Marijuana legalization advocates say they’ve had the best week in Washington since — well, ever. And it’s thanks to politicians on both sides, including the president, suddenly embracing efforts to help more states legalize marijuana.

“I think we reached critical mass among the population years ago,” said Don Murphy, the director of conservative outreach for the Marijuana Policy Project, “but I think we are finally reaching critical mass on Capitol Hill now.”

Consider:

Senate Minority Leader Charles E. Schumer (D-N.Y.) announced Friday that he has decided to support decriminalizing marijuana at the federal level and will advocate bills to help marijuana businesses grow (no pun intended). Schumer cited an “evolved thinking — both personally and by the nation” for his switch. As The Washington Post’s David Weigel writes, “It’s the first time that a leader of either party in Congress has endorsed a rollback of one of the country’s oldest drug laws.”

The Friday before, President Trump promised a Senate Republican from Colorado that he would protect states that have legalized marijuana. That’s in stark contrast to what Trump’s attorney general did earlier this year by rolling back Obama-era protections allowing states to create their own marijuana laws without fear of prosecution from the federal government. (The federal government says marijuana is illegal.) Trump’s position on reconciling the different laws was vague before this.

This week, the House of Representatives held one of its first hearings ever on legislation to roll back medical marijuana regulations.

And last week, former Republican House speaker John A. Boehner pulled a stunning 180 from his days in Congress and announced that he had joined the board of directors of a cannabis company. Boehner had once said he was “unalterably opposed” to decriminalizing marijuana because it would lead to more people abusing it, alcohol and other drugs.

Legalization advocates say there is no one thing that has happened recently to spark these politicians to suddenly switch from their long-entrenched views. But there is plenty of evidence of states and public opinion moving, rather rapidly, in favor of marijuana legalization, and perhaps the politicians in Washington are taking notice.

All but two states have laws on the books at least recognizing the value of medical marijuana. Medical marijuana is legal in 29 states. Recreational marijuana is legal in nine states and the District, and advocates are optimistic that the number could double by the 2020 presidential election.

An October Gallup poll found record-high support for legalizing marijuana, including among Republicans:


“The politics of it are making more sense every day,” Murphy said, “even among Republicans.”

In Michigan, Republican lawmakers are considering legalizing recreational marijuana rather than letting an initiative that’s gaining steam make the ballot this fall. GOP lawmakers fear that the ballot measure would boost Democratic turnout in November, reports the Detroit News. That would make Michigan only the second state where marijuana has been legalized by the legislature, after Vermont did so earlier this year. That bill was signed by a Republican governor, Phil Scott.

In the fall, voters in Oklahoma and Utah will consider marijuana measures. In 2016, voters in Arkansas, North Dakota and Florida overwhelmingly approved medical marijuana legalization. Those are all states Trump won.

It’s probably less of a surprise that Democratic gubernatorial and attorney general candidates are practically tripping over themselves to support marijuana legalization, said Karen O’Keefe of the Marijuana Policy Project.

In Schumer’s home state of New York, Gov. Andrew M. Cuomo (D) is facing a primary challenger, Cynthia Nixon, who has made marijuana legalization a central feature of her campaign. Cuomo initiated a statewide study this year on what legalizing marijuana would mean for New York.

Of course, not everyone in Washington suddenly wants to see pot legalized everywhere. On Friday, to counter the 4/20 programming, Smart Approaches to Marijuana held a news conference in downtown D.C. to reiterate its opposition to marijuana legalization. The group’s director, Kevin Sabet, said SAM would be ramping up its federal lobbying efforts and will soon call on support from families suffering from the national opioid crisis, “80 percent of whom will tell you marijuana had a role to play.”

The fact is, said Sabet and Rafael Lemaitre, a former spokesman for the Obama White House drug office, is that a nascent marijuana industry has poured millions of dollars into lobbying.

“We can’t take it for granted anymore” that politicians will reject marijuana legalization, Sabet said in an interview with The Fix, “but we also don’t think it's inevitable.”

But opponents appear to be fighting a losing battle at the moment. Election-year politics can never be entirely separated from politicians’ decisions. It’s possible Schumer is watching what’s happening in his home state and the overwhelming support for legalization within his own party, and decided that backing marijuana could boost the chances of Democrats taking back control of the Senate in November.

Whatever the reason, O’Keefe said, “we’re seeing politicians’ evolution on this issue quickly.”

So quickly, apparently, that even glacial-paced Washington is starting to take notice.