By Bob Salsberg, Associated Press

BOSTON (AP) — Voters have approved a ballot measure making Massachusetts the first state in the eastern U.S. to legalize the recreational use of marijuana.

A similar question is leading in Maine.

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The results of those ballot questions — and votes being taken in California, Arizona and Nevada — could represent a key turning point in the legalization movement nationwide. Recreational marijuana is currently allowed in four western states: Colorado, Washington, Oregon and Alaska. The drug remains illegal under federal law.

Both Massachusetts and Maine previously voted to decriminalize possession of small amounts of marijuana and to authorize medical marijuana programs.

Opponents of the ballot questions contended passage would result in an unlimited number of marijuana retail stores and allow those pot shops to sell high-potency marijuana edibles, some of which could end up in the hands of children because of their resemblance to candy or other treats.

Critics also said marijuana can be a gateway drug to more dangerous or addictive narcotics like heroin, and that increased marijuana use would lead to more traffic crashes.

Backers countered that removing prohibitions on adult use marijuana would largely remove the drug from the black market and generate a new stream of tax revenue.

Massachusetts Democratic Senate President Rosenberg, who supported the question, said he looks forward to working with top lawmakers “to create a best-in-the-nation law that protects public safety while respecting the wishes of the voters.”

Rosenberg has said that lawmakers may need to tweak the question.

Opponents said they respected the decision of voters.

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“Our goal throughout this campaign was to make sure people knew what they were voting on — that Question 4 wasn’t just about legalization, but the commercialization of marijuana in Massachusetts,” said Nick Bayer, campaign manager for the Safe and Healthy Massachusetts campaign.

The initiatives in Massachusetts and Maine would regulate and tax marijuana in ways similar to alcohol. But there are differences in the way the two New England states would proceed under the respective measures.

In Massachusetts, the licensing authority for recreational marijuana would be a new three-member Cannabis Control Commission, appointed by the state treasurer. The commission would be advised by a Cannabis Advisory Board with 15 members appointed by the governor.

In Maine, recreational marijuana would be regulated by the existing state Department of Agriculture, Conservation and Forestry.

Maine would allow people 21 years of age or older to possess up to 2 1/2 ounces of marijuana and cultivate up to six pot plants in their homes. Massachusetts would allow an individual 21 or older to possess 1 ounce of pot outside their home and up to 10 ounces inside their homes, and to cultivate up to six plants for personal use.

Both states would bar marijuana use in public.

The Massachusetts proposal called for a 3.75 percent surcharge on retail sales of marijuana, on top of the state’s regular 6.25 percent sales tax. Local jurisdictions could also add up a 2 percent tax, creating a combined maximum tax of 12 percent on pot products.

Maine’s proposal called for a flat 10 percent sales tax on retail marijuana.

The taxes in both states would pale compared to the 28 percent effective tax rate in Colorado and 37 percent in Washington state.

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Opponents in Massachusetts have questioned whether the tax would be sufficient to even cover regulatory costs associated with legalization, let alone generate additional revenue for education, transportation or other needs.