Colorado and Washington state voted to legalize the possession and sale of marijuana for recreational use Tuesday, becoming the first states to defy the federal ban on the substance.

The two ballot initiatives push forward a cause long fought by legalization advocates, who liken the ban to the prohibition of alcohol and point to the drug’s economic and health benefits.

It’s also a rebuke of the decades-long federal crackdown on cannabis, which the Justice Department has called a “dangerous drug.”

The move could also set up a duel between states and the federal government, which plans to enforce federal law. Jonathan Turley, a professor of public interest law, said it will test the Obama administration’s aggressive enforcement of the law.

“The Obama administration pulled back on the issue when courting votes from liberals during the election. This was one of a number of complaints against Obama,” Turley said.

A day after the election, he said, Attorney General Eric Holder’s staff said it would continue the same policies from before – seen as a continuation of the federal crackdown.

Colorado Gov. John Hickenlooper pointed to the federal ban and advised residents to not “break out the Cheetos or Goldfish too quickly.”

Colorado’s Amendment 64, which passed with 53 percent, strips away criminal penalties for marijuana use by anyone over the age of 21. It also allows adults to grow up to six marijuana plants in their homes, but does not outline regulations for the industry.

Washington’s Initiative 502 would also regulate the sale and distribution of cannabis, charging the state’s liquor agency with handing out licenses to marijuana farmers.

Both legalize possession of one ounce of marijuana for private use.

Phil Gardner, a senior from University Place, Wash., said the state’s “history of supporting personal liberties” made it no surprise that it would lead the way with marijuana legalization.

“The deal with the marijuana initiative here was there was never organized opposition to it,” said Gardner, who took a semester off to work in Washington state politics.

“It was a very one-sided conversation. Because of that, it never got a lot of media attention because there was never any good conflict to write about.”

Instead, the state was mostly focused on its governor’s race and marriage equality amendment that passed, Gardner added.

The two ballot approvals could signify a watershed moment for legalization supporters. According to a Gallup poll last year, 50 percent of voters approve of making marijuana legal, with 46 percent opposed.

The sentiment around the country was more mixed. Oregon voted down a proposal to legalize recreational marijuana use. Massachusetts approved a measure to allow medical marijuana use, while Arkansas voted one down.

Seventeen states and D.C. allow the use of medical marijuana.