The legalized-marijuana movement will likely welcome the news Wednesday that two prominent former politicians are joining a cannabis company.

John Boehner, former Republican speaker of the House of Representatives, and Bill Weld, a former Republican governor of Massachusetts who was the 2016 running mate of Libertarian presidential candidate Gary Johnson, are joining the advisory board of Acreage Holdings, which owns cannabis licenses and assets in the 30 states where cannabis is approved for medical or recreational use.

Boehner tweeted that he was making the move because his thinking on cannabis has evolved, and that treating it more leniently under the law could help in the battle against America’s opioid crisis.

“ ‘I’m convinced de-scheduling the drug is needed so we can do research, help our veterans, and reverse the opioid epidemic ravaging our communities.’ ” — John Boehner, on Twitter

Cannabis is still illegal at the federal level and is labeled a Schedule I substance, alongside heroin and LSD. That prohibition has made it difficult for an industry to evolve as growers, dispensaries and others who handle the substance are unable to open accounts at banks that have federal backing.

In case you missed it:The startup burning $1 million a month in hopes of selling $1 billion of pot a year

As cannabis gains acceptance — 94% of Americans currently favor some type of access, according to a joint statement from Boehner and Weld — more parties are calling for it to be de-scheduled and free up companies to engage in research and development. With Canada gearing up to fully legalize marijuana this summer, there are concerns that U.S. companies will lose out on capturing a share of a market expected to generate billions in sales, and that states will lose a valuable source of tax revenue.

“While the Tenth Amendment has allowed much to occur at the state level, there are still many negative implications of the Federal policy to schedule cannabis as a Class 1 drug: most notably the lack of research, the ambiguity around financial services and the refusal of the VA to offer it as an alternative to the harmful opioids that are ravishing our communities,” said the statement.

The industry is facing one major obstacle in Attorney General Jeff Sessions, a longtime cannabis opponent. In January, Sessions rescinded an Obama-era policy used as a protection for states that have legalized marijuana.

Read now:Congress gives medical marijuana users a good reason to be paranoid

Also:Jeff Sessions has delivered a blow to the marijuana industry’s ability to raise capital

Related:Marijuana industry could be worth $50 billion annually by 2026

The Justice Department scrapped what is known as the Cole Memo, a four-page document written by Obama-era Attorney General Eric Holder’s office that outlined how the federal government would enforce marijuana laws, stating that Washington would not interfere with states that legalize recreational and/or medical marijuana, as long as they adhere to a set of guidelines.

Don’t miss:Corona beer parent’s move into the marijuana business is a smart one

What every cannabis investor should be paranoid about

The news sent cannabis-related stocks sharply lower.

The Canada-based Horizons Marijuana Life Sciences ETF HMMJ, +2.15% has gained 59% in the last 12 months, while the S&P 500 SPX, +1.05% has gained 14% and the Dow Jones Industrial Average DJIA, +0.51% has risen 20%. Ontario-based Canopy Growth Corp. WEED, +1.77% has gained 206%, and Colorado-based farmer GrowGeneration Corp. GRWG, -1.38% has gained 129%.

Everything you need to know to invest in marijuana

See now:How 4/20, the stoner’s holiday, went mainstream

Also:How investors can separate the winners from the losers in the marijuana industry

Don’t miss:These are the cheapest countries in the world to buy drugs and alcohol