Support for marijuana legalization is quickly becoming a mainstream consensus position in the Democratic Party.

Two of the party’s leading potential 2020 presidential candidates joined together this week in support of far-reaching legislation that would end the federal prohibition of cannabis and encourage states to legalize the drug.

“Legalizing marijuana isn’t a matter of if, it’s a matter of when,” Sen. Cory Booker (D-NJ) said about the legislation, the Marijuana Justice Act, which he introduced last August.

Sen. Kirsten Gillibrand (D-NY), who signed onto the bill as a cosponsor on Wednesday and did a Facebook Live chat with Booker about it, called cannabis legalization “a social justice issue and a moral issue that Congress needs to address.”

The vocal pro-legalization support from the two senators, who are widely considered to be weighing campaigns for the Democratic presidential nomination in 2020, signals that a shift toward marijuana reform advocacy that has been underway in the party for some time is elevating to a near consensus.

And polling shows that Democratic voters are in support of the move.

Gallup found last year that 72 percent of Democrats back marijuana legalization, and a Quinnipiac University survey last month showed that 95 percent of the party’s voters support medical cannabis.

The latter poll also showed that just 12 percent of Democrats want the federal government to interfere with the implementation state marijuana laws.

Sen. Bernie Sanders, a Vermont independent who caucuses with Democrats, also supports legalization. The senator, who introduced legislation to deschedule marijuana during his nearly successful campaign for the party’s 2016 presidential nomination, is reportedly considering another run in 2020.

Last week, Sanders’s campaign organization launched an online petition calling for an end to marijuana prohibition and the broader “war on drugs.”

Democrats’ march toward legalization seems to have been accelerated by the Trump administration’s anti-cannabis moves.

While Trump pledged during the campaign that he would respect local marijuana laws if elected, Attorney General Jeff Sessions last month to tore up Obama-era guidance that has generally allowed states to implement their own laws without federal interference.

A large number of members of Congress from both parties, but Democrats in particular, immediately criticized the Justice Department reversal.

“The Attorney General’s decision to rescind the Cole memo was a very bad one & I oppose it,” Senate Democratic Leader Chuck Schumer (NY) tweeted. “I believe that the States should continue to be the labs of democracy when it comes to recreational & medical marijuana. Jeff, this is one place where states’ rights works. Let each state decide.”

House Democratic Leader Nancy Pelosi also slammed the move, tweeting, “Attorney General Sessions, your unjust war against Americans who legally use #marijuana is shameful & insults the democratic processes that played out in states across the country.”

But while most Democratic lawmakers tend to vote in support of marijuana proposals in Congress, the party is by no means unanimous on the issue.

Longtime Sen. Dianne Feinstein (D-CA), for example, is one of Congress’s most ardent opponents of marijuana law reform, and has voted against amendments to protect her state’s medical cannabis law from Justice Department intervention. She also vigorously campaigned against marijuana reforms at the state level.

And some Democrats were upset that congressional leaders chose Rep. Joe Kennedy III (D-MA), who opposes legalization, to deliver the party’s response to President Trump’s first State of the Union address last month.

As a member of Congress, Kennedy has not only opposed his state’s move to legalize marijuana, but has voted against amendments to shield state medical marijuana laws from federal interference, allow military veterans to access medical cannabis and protect children who use non-psychoactive cannabidiol extracts to treat severe seizure disorders.

Kennedy knows that his views on cannabis are out of step with the party.

“I come at it a little bit differently, obviously, than the vast majority of my colleagues,” he said in an interview. “I think the party is clearly moving in that legalization direction. It might already be there.”

But legalization isn’t strictly a Democratic issue.

Several Republican lawmakers have taken leadership roles in efforts to end federal cannabis prohibition.

Sen. Cory Gardner (R-CO), for example, has gone so far as to actively block Justice Department nominees from being confirmed in protest of Sesssion’s move. In a speech this week, Sessions called the dispute “frustrating” and implied that Gardner is prioritizing marijuana over national security.

While support for marijuana law reform is growing across party lines — Gallup’s recent poll found for the first time that a bare majority of Republicans now back ending prohibition — Democratic voters and elected officials are so far more likely to favor legalization.

But although the party’s platform adopted in 2016 included a plank calling for “a reasoned pathway for future legalization,” that year’s Democratic presidential nominee, Hillary Clinton, only went as far as voicing vague support for respecting state laws and slightly downgrading cannabis’s federal status.

And not all rumored 2020 contenders have embraced legalization like Booker, Gillibrand and Sanders have. At least not yet.

While another potential 2020 Democratic presidential candidate, Sen. Kamala Harris (D-CA), like Sanders, also recently launched an online petition about marijuana, she hasn’t yet added her name onto any bills to change cannabis’s status under federal law.

Her position does seem to be evolving, though.

In 2014, as state attorney general, Harris simply laughed in a reporter’s face when asked about her position on legalization. But now she is signing letters calling on the federal government to respect state laws and cosponsoring legislation to allow banks to serve state-legal cannabis businesses.

Sen. Elizabeth Warren (D-MA) — another potential 2020 contender — is also cosponsoring the banking bill and has signed onto broader legislation to allow states to implement medical marijuana policies.

A lot can happen before the 2020 Democratic National Convention, but it’s a safe bet that the party’s next presidential nominee will at least have a more far-reaching marijuana reform position than that of their 2016 candidate.

This piece was first published by Forbes.