Three legislators are kicking off the debate to legalize marijuana for recreational use, although they take different routes to get there.

Rep. Raymond Dehn, D-Minneapolis, wants to put the issue before the voters as a constitutional amendment on the 2020 ballot, which would first require approval from both the DFL-controlled House and the majority Republican state Senate.

Rep. Mike Freiberg, D-Golden Valley, and state Sen. Melisa Franzen, D-Edina, are working on measures that would legalize marijuana, with the Legislature directing the Department of Health to write regulations to mitigate negative consequences.

Legalization continues to gain momentum across the country, with Michigan legalizing at the end of 2018, and Illinois electing a pro-legalization governor in Democrat J.B. Pritzker. Recreational marijuana use is now legal in 10 states, including the entire West Coast and Maine and Massachusetts in the east.

In Minnesota, two pro-legalization statewide candidates won 5 percent of the vote in the November election, granting them major party status. Democratic Gov. Tim Walz is the first Minnesota governor to publicly indicate support for legalizing recreational marijuana, giving activists fresh hope the state might pass the measure this year.

But Minnesota opponents are lining up against legalization.

A group called Smart Approaches to Marijuana Minnesota, with the stated mission of “stopping marijuana from becoming the next Big Tobacco,” held a news conference at the Capitol last week including law enforcement and people negatively affected by marijuana — only to be shouted down by pro-legalization demonstrators.

Opponents are concerned about crime, more people driving under the influence of marijuana, the link between mental illness and cannabis and a newly empowered industry marketing the product to teenagers and lobbying against restrictions.

“Anything that becomes legalized and commercially available gets in the hands of teenagers,” Kim Bemis, chairman of Smart Approaches to Marijuana Minnesota, said in an interview Monday.

The path to legalization in Minnesota will likely face obstacles from Senate Republicans.

“It’s important to consider the many negative consequences that come with legalizing recreational marijuana,” state Sen. Paul Gazelka, R-Nisswa, the majority leader, said in a statement to the Star Tribune in late 2018. “We must have a long conversation about these real consequences.”

A recent book by the journalist Alex Berenson called “Tell Your Children: The Truth About Marijuana, Mental Illness, and Violence” and accompanying essays in national publications have fueled fierce debate among social scientists about the truths of his arguments, which draw connections between cannabis use, psychosis and violence.

Dehn said prohibition doesn’t stop people from using the drug.

“We know cannabis is being used illicitly right now. I understand there are people negatively impacted, just as people are negatively impacted by alcohol,” he said.

Dehn, whose personal history includes being pardoned for drug-related burglary he committed in the 1970s, said the drug war has unjustly ensnared young black men and prevented them from full citizenship.

“If I had the same set of experience but had been a young black man, I don’t think my future would have been the same,” Dehn said.

Freiberg said he understands the potential problems with legalization, which is why he wants the Department of Health to regulate cannabis.

“I don’t want this to be like Big Tobacco, where it’s manipulated to be more addictive, made with appealing flavors and marketed to kids,” Freiberg said.

In several states that have legalized cannabis, products are sold as candy, ice cream and soda. While products have proliferated, prices have collapsed.

It’s unclear when Minnesota lawmakers would take up legalization. Walz and Democratic lawmakers have said their main focus this year is crafting a two-year budget that is expected to be nearly $50 billion and will fund schools and colleges, public health care, parks and natural resources and other programs.