PORTLAND — Campaigners who want to legalize marijuana in Maine are opening their headquarters in the state’s largest city.

Maine residents can decide if they want to vote “yes on 1” this November to legalize marijuana use and possession. The law would apply for those at least 21 years old.

The pro-marijuana campaigners will open their office in Portland on Thursday evening. They will use an opening ceremony to recruit volunteers and reach out to supporters.

Pro-legalization advocates have won a pair of municipal-level legalization victories in referendums in Portland and South Portland. A similar measure failed in Lewiston, the state’s second-largest city.

Maine also decriminalized the possession of small amounts of marijuana decades ago and medical marijuana is legal in the state.