GREENFIELD — The vote to legalize marijuana — state ballot Question 4 — came down to the wire Tuesday night.

With about a third of votes counted at 10:15 p.m. the tally was neck-and-neck: 53-percent “yes,” 47-percent “no.”

“It looks like it’s going to pass, and I hope it does,” said Wendell resident Patti Scutari, a medical marijuana patient. A few months ago, Scutari and her partner, Francesco “Apollo” Kompagnone’s medical marijuana plants were raided. “We’re very hopeful that it’ll pass so that in the future, no one will have to deal with what we’ve had to deal with.”

“I will very modestly and cautiously predict that Question 4 will prevail. We have gained encouragement, but all of that encouragement is totally eclipsed by this feeling of dread of what’s happening elsewhere,” said Dick Evans, chair of the Yes on 4 committee.

Proponents of Question 4 have pitched the legal-marijuana industry to state voters as one similar to alcohol sales. The idea behind legalization is to eliminate the black market for marijuana, which proponents say poses more dangers than does legalization. Essentially, proponents argue that because people are going to use marijuana anyway, legalization will allow state lawmakers to regulate and tax it.

Opponents of the bill fear that legalizing marijuana could lead to an increase in hard drug use — commonly referred to as the “gateway drug” effect. In the past, they’ve also raised concerns that legalization could introduce to young people risky edible marijuana products easily mistaken for normal snacks.

The results of the ballot question — and similar votes being taken in Maine, 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.

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 calls 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 calls 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.

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