BOSTON (Reuters) - Massachusetts on Thursday became the first state in the densely populated U.S. Northeast to legalize marijuana for recreational use, a step that advocates say could help spread the drug’s acceptance across the United States.

The state is one of three where ballot measures legalizing recreational use of the drug passed on Nov. 8, along with California and Nevada, while voters in Arizona rejected it and a Maine ballot is still being recounted.

The Massachusetts measure legalizing use of the drug by adults 21 and older in private places passed by 54 percent to 46 percent, easily overcoming the opposition of prominent state officials in both parties.

Massachusetts is now one of eight U.S. states that have legalized use of the drug for recreational use since voters in Washington and Colorado first approved the idea in 2012. But the measure approved last month does not allow the drug to be sold in the state legally until 2018, a delay that advocates said was intended to give state officials time to determine how to implement the law.

Distances between cities in the Northeast are smaller than in the West, leading some to suggestMassachusetts’ move could motivate neighboring states to consider similar steps, given how easy it will be for people to cross state lines to acquire the drug.

“It certainly makes sense for those states to look at the policy and consider the benefits that a state gets from putting this behind a regulated counter,” Taylor West, deputy director of the Washington-based National Cannabis Industry Association, said in a phone interview.

Neighboring Rhode Island’s governor, Democrat Gina Raimondo, has said she will more closely consider the idea of legalization following Massachusetts’ move.

An October poll by Gallup showed that 60 percent of Americans now support the legalization of recreational use of marijuana. Even more approve of the idea of legalizing marijuana for medical use, a step that 28 states have taken.

Nonetheless, the drug is illegal under federal law, and U.S. President-elect Donald Trump, who takes office on Jan. 20, has sent mixed signals about his views on it.

During the campaign, Trump, a Republican, said that marijuana legalization was best left to the states. His pick for attorney general, U.S. Senator Jeff Sessions of Alabama, has criticized Democratic President Barack Obama’s administration for not enforcing the federal ban aggressively enough.

“When you look at Jeff Sessions’ comments around marijuana, you can’t help but be worried,” Jim Borghesani, who ran the campaign to legalize marijuana in Massachusetts, said in a phone interview. “Until we see the way they are going to move, it’s difficult to say.”

(Reporting by Scott Malone; Editing by Jonathan Oatis)