David Boyer has challenged South Portland Police Chief Edward Googins to a “hit for shot” duel in a public park. For every shot of alcohol Googins takes, Boyer would take a toke of marijuana, and the crowd would decide who was in worse physical condition in the end.

Boyer is not some college kid, acting out. He's the Maine political director of the Marijuana Policy Project (MPP), and he's using an approach that's been an election-winner before.

In 2012, Colorado voters approved a ballot measure legalizing marijuana. The state broke new ground in the ongoing battle over narcotics policy, and the referendum's success validated the innovative technique of comparing cannabis to alcohol. Now that message is being deployed in marijuana-related elections in Alaska and Oregon as well as in Maine, and these ballot initiatives are in advance of a broader multistate push in 2016.

Boyer proposed the "drug duel" after Police Chief Googins announced his opposition to a municipal referendum to legalize marijuana possession. “Claims that marijuana is safer than alcohol are so bogus, it’s not even funny,” Googins told the Bangor Daily News.

“We have done everything in our power to highlight the danger associated with laws that steer adults toward drinking by threatening to punish them if they make the safer choice to use marijuana,” Boyer said in a press release. “Enough is enough. Perhaps this dramatic demonstration of the relative harms of each substance will finally get the point across.” Boyer promised to bring “enough alcohol to kill a man” to the duel.

Googins isn't playing along. “Any type of challenge like this isn’t going to prove a thing other than that people can get high or get drunk,” he said. In a follow-up email, he added of the duel proposal: "I can tell you I don’t violate several local and state laws in a public park when requested. I spend my time enforcing the law."

The "drug duel" concept, urging voters to weigh the relative dangers of cannabis and alcohol, is the brainchild of MPP officials Steve Fox and Mason Tvert. (Fox has since left the group.) In the years leading up to Colorado's historic legalization vote, Tvert slammed politicians such as Democratic Colorado Gov. John Hickenlooper and 2004 GOP U.S. Senate candidate for Colorado Pete Coors for opposing marijuana legalization when they had made their personal fortunes selling alcohol. He challenged both men to drug duels.

After marijuana legalization campaigns failed in Nevada and California, Tvert and Fox persuaded advocates in Colorado to explicitly frame the 2012 campaign around the alcohol vs. marijuana comparison. Ultimately, the official name of the successful state ballot initiative was the Regulate Marijuana Like Alcohol Act of 2012.

Tvert said that in a state with a beer brewer governor, a burgeoning craft beer industry and a professional baseball stadium named after a brand of alcohol, the strategy helped voters become comfortable with the idea of legalizing a mind-altering product.

“The message is simple: If we can regulate alcohol, we can regulate a far less harmful substance,” he said. “Marijuana has been illegal because too many people think it is too dangerous to allow adults to use, when in fact it is less harmful than alcohol.”

Since the Colorado vote, that message has gained political traction. From crime research to hospital data to morbidity statistics, there is plenty of evidence to support the assertion -- although researchers are still investigating the differing health effects of inhaled vs. ingested marijuana, and pot consumers are often unaware of the potency of any given purchase.

In January, the New Yorker reported that President Obama said, “I don’t think [marijuana] is more dangerous than alcohol.” A few months later, the Pew Research Center released a poll showing that 69 percent of Americans say alcohol is more harmful to people’s health than marijuana.

In this election cycle, the alcohol-marijuana comparison is defining legalization campaigns in two Maine cities. Voters in Lewiston and South Portland will decide on a legalization initiative similar to the one that Portland, Maine, passed last year -- and similar to one that could be on the statewide ballot in 2016.

In Alaska, the organization behind the “Yes on 2” initiative has named itself the Campaign to Regulate Marijuana Like Alcohol and has sponsored bus ads promoting the idea that marijuana is the safer substance.

Though much of the legalization campaign in Oregon has focused on public safety, activists designed that initiative to invoke the alcohol comparison. Their proposal would have the Oregon Liquor Control Commission expand its regulatory oversight to marijuana.

“Everyone recognizes that alcohol prohibition was a huge failure,” says Tvert, whose organization has created committees focused on the 2016 elections in Nevada, Arizona, Massachusetts and California. “Our point is that marijuana prohibition has been just as big of a disaster.”