Marijuana legalization keeps rolling. The legalization of recreational marijuana was on the ballot in five states yesterday. The people of California, Massachusetts, and Nevada voted to legalize. As of this writing, legalization maintains a slim, too-close-to-call lead in Maine as well. Legalization failed in Arizona by a small margin.

Beyond legalizing marijuana in America’s most populous state, the vote in California also means the entire West Coast has now rejected marijuana prohibition. The vote in Massachusetts makes it the first state east of the Rocky Mountains to do the same.

In addition, medical marijuana was legalized in Arkansas, Florida, and North Dakota, while restrictions on medical marijuana were relaxed in Montana. In Oklahoma, which prides itself on being “the reddest state in the nation” (Donald Trump won every single county last night), voters passed an amendment to state law that recategorizes a variety of drug offenses from felonies to misdemeanors.

All of these developments speak to a growing (and increasingly bipartisan) acknowledgment that Americans are tired of the failed drug war, and especially the government’s crusade against marijuana. More people are arrested for marijuana offenses than for all violent crimes combined in this country, and voters increasingly think it’s time to put a stop to it.

As my colleague Jeff Miron points out, marijuana prohibition is predicated on myths. The allegations that marijuana legalization leads to huge increases in use; causes increases in crime, traffic fatalities, and addiction; and leads to abuse of other, harder drugs simply do not comport with the data we’ve seen from legalization policies in the U.S. and around the world.

Despite this building momentum for reform, last night also injected a bit of uncertainty into the prohibition discussion. Marijuana remains illegal under federal law. The Supreme Court has already ruled that federal marijuana prohibition is constitutional, state-level legalization notwithstanding (although Congress has put temporary limits on federal funding for that purpose). As a result, the progress we’ve seen thus far has depended on President Obama’s commitment to respect the will of the states when it comes to marijuana enforcement. Essentially, President Obama has refused to enforce federal marijuana laws when those laws conflict with legalization bills passed by state voters.

President-elect Trump is not required to continue that commitment. He, along with his pick for Attorney General, could decide to begin enforcing federal marijuana laws in states that have voted to legalize (provided Congress provides funding), in which case the successful experiments in legalization would end virtually overnight. The more states legalize marijuana, however, the less likely it seems that the federal government will try to force the cat back into the bag. 

President-elect Trump should let the state experiments play out, and respect the will of the American voters who increasingly reject the failed policy of prohibition.