The Washington Post via Getty Images Voters in eight out of nine states that went to the polls on the issue of marijuana reform voted to roll back longstanding restrictions on the drug.

Election night brought several astonishing, wholly unforeseen results. But let’s put the presidential campaign aside for a second and talk about weed.

Marijuana was on the ballot in nine states on Tuesday. Voters in eight of those states went to the polls and approved measures to roll back longstanding restrictions on the drug, delivering a historic victory for marijuana police reformers.

By the end of the night, four states approved recreational marijuana, with California, Nevada, Massachusetts and Maine all rejecting prohibition and opting to tax and regulate the drug instead. The efforts doubled the number of states with legal weed, bringing the total to eight, which are home to nearly a quarter of the nation’s population. Florida, Arkansas, North Dakota and Montana also voted on marijuana for medical use, bringing the total to 28 states and Washington, D.C.

Only Arizona, which was considering recreational marijuana legalization, voted down their measure on Tuesday.

Ji Sub Jeong/Huffington Post

The results, as well as the scale of the successes ― which saw measures like Florida’s passed by huge double-digit margins ― will give a shot in the arm to the campaign for legalization and reform, said marijuana policy experts.

“This is the most momentous Election Day in history for the movement to end marijuana prohibition,” said Rob Kampia, executive director of Marijuana Policy Project. “These votes send a clear message to federal officials that it’s time to stop arresting and incarcerating marijuana users. Congress must take action to ease the tension between state and federal marijuana laws.”

The trend of state-level legalization reflects a broader cultural shift toward acceptance of marijuana, the most commonly used illicit substance in the United States. National support for the legalization of marijuana has risen dramatically in recent years, reaching historic highs in multiple polls just last month. States like Colorado have established regulated marijuana marketplaces, and successes there have debunked some lawmakers and law enforcers’ predictions that such polices would result in disaster.

The progress we’ve made ... will be very much at risk when Donald Trump enters the White House.

Still, the federal government continues to ban cannabis, classifying it in Schedule I as one of the “most dangerous” drugs, alongside heroin and LSD. States have been able to forge ahead on legalization despite the federal ban, helped in part by federal guidance that urged prosecutors to refrain from targeting marijuana operations that are legal under state law.

President Barack Obama has suggested the government may soon need to reassess its position. In an interview with “Real Time” host Bill Maher on his show that aired last week, Obama said successes in the legalization movement should lead to “a more serious conversation about how we are treating marijuana and our drug laws generally.”

“If, in fact, [marijuana legalization] passed in all these states [on Tuesday], you now have about a fifth of the country that’s operating under one set of laws, and four-fifths in another,” Obama said. “The Justice Department, DEA, FBI ― for them to try to straddle and figure out how they’re supposed to enforce laws in some places and not in others — they’re gonna guard against transporting these drugs across state lines, but you’ve got the entire Pacific corridor where this is legal — that is not gonna be tenable.”

But soon, federal marijuana policy will be in President-elect Donald Trump’s court. Trump has said he would respect states’ rights on the issue, but his potential incoming administration has some marijuana reformers worried.

Ethan Nadelmann, executive director of the Drug Policy Alliance, said he was deeply concerned because Trump’s most likely appointees to senior law enforcement positions ― former New York City Mayor Rudy Giuliani and New Jersey Gov. Chris Christie ― and Vice President-elect Mike Pence “are no friends of marijuana reform.”

“The progress we’ve made, and the values that underlie our struggle ― freedom, compassion, reason and justice ― will be very much at risk when Donald Trump enters the White House,” he said.

Giuliani has called legalizing marijuana in any form a “mistake.” And Christie said if he were president, he would “crack down” on legalization and “enforce the federal laws.” Both men have been rumored to be in line for cabinet positions in the Trump Administration, perhaps attorney general.

Tom Angell, chairman of drug policy reform group Marijuana Majority, said he expects Trump to hold true to his pledge not to interfere with existing state laws.

“Trump has clearly and repeatedly pledged to respect state marijuana laws, and we fully expect him to follow through on those promises, not only because it is the right thing to do but also because these reforms are broadly supported by a growing majority of voters,” Angell said. “Reversing course and going against the tide of history would present huge political problems that the new administration does not need.”

Clarification: Language has been amended to reflect that the vote in Montana expanded aspects of, rather than established, marijuana for medical use.