A Colorado marijuana innovation is changing the way lawmakers in even the most conservative parts of the country talk about cannabis and is poised to create a rapid expansion in the number of states that have legalized marijuana in some way.

But many marijuana advocates view the new political campaign with skepticism, fearing it could halt their movement's momentum.

The invention is a non-psychoactive oil made from marijuana plants that is used to treat children with severe seizure disorders. The oil is rich in a chemical called cannabidiol, or CBD, but is low in THC, the main psychoactive ingredient in marijuana.

Spurred by parents of epileptic children, legislatures in at least a dozen states so far this year have or will consider bills about the marijuana oil. Last week, the governor of Utah signed into law a bill legalizing possession of the oil. A bill in Alabama has passed the Legislature and is awaiting the governor's signature. Lawmakers in Kentucky, Florida, South Carolina, Wisconsin and other states have or will consider CBD bills this year.

"What the CBD movement has done, I think, is brought in the soccer moms to the discussion," said Josh Stanley, one of a family of Colorado brothers who own a medical marijuana business and developed the oil. "It's brought in the mainstream, and it's brought in the conservatives."

But, even though the bills amount to the most successful discussions ever held about marijuana legalization in some of the states where they are being considered, the nation's largest marijuana-reform groups view them with skepticism.

The deputy director of the National Organization for the Reform of Marijuana Laws has criticized them as "unworkable" and without real benefits. A policy manager for the Drug Policy Alliance is concerned the bills will leave other reform efforts behind.

"Is it better than nothing?" asked Mason Tvert, the national spokesman for the Marijuana Policy Project and one of the leaders of the marijuana legalization campaign in Colorado. "Potentially. But if it means there is no longer a pressing need for comprehensive medical marijuana legislation, these will be a net negative."

More restrictive

Currently, 20 states and the District of Columbia have legalized medical marijuana. Because the CBD oil is derived from marijuana plants, states that legalize it will also be crosswise with federal law. But because the CBD laws are far more restrictive than typical medical marijuana laws, advocates on all sides of the issues aren't putting states that pass them in the medical marijuana column.

What the CBD bills have exposed is the long-standing tension within the marijuana movement.

Struggling to generate interest for broader marijuana legalization in the mid-1990s, activists instead got behind more limited medical marijuana initiatives. Since then, reform campaigns have taken on a well-established multiyear pattern: medical marijuana, then dispensaries, then full legalization.

But activists have long feared that, taken to its logical conclusion, medical marijuana could be a "box canyon" for broader legalization efforts. Basically, if more refined medicines derived from marijuana are available, why should lawmakers allow people to grow pot at home?

That is exactly where many activists worry the CBD bills will take their movement — and, perhaps not coincidentally, exactly where people opposed to legalization hope it will go.

"The question is not if but how," said Kevin Sabet, the executive director of the group Smart Approaches to Marijuana. "How do we deliver it to families?"

Sabet, whose group opposes marijuana legalization, said he supports further research into and medical development of CBD treatment. But he said that should occur within the established medical processes, something he said the federal government is increasingly willing to expedite.

One pharmaceutical drug — made from 100 percent CBD derived from marijuana plants — has been cleared for clinical trials. The only lab in the country with federal approval to grow marijuana, at the University of Mississippi, will reportedly start growing more CBD-rich strains for researchers to study.

"Used as pawns"

Sabet said using CBD bills to create interest in marijuana legalization is cynical.

"I think you have a lot of people here who are being used as pawns by the broader legalization movement," he said.

Tvert, however, said the cynicism lies on the other side. He points to Minnesota, where the governor has proposed a study on CBD in lieu of broad medical marijuana legalization and parents backing medical marijuana have called the move disingenuous.

"It raises the question of whether these CBD-only bills are good enough," Tvert said.

Even Stanley acknowledges the bills will likely have little immediate impact. The Utah law, for instance, allows parents to possess the oil in that state if a neurologist has said their children will benefit from it. But the law contains no provision for growing marijuana in Utah or making the oil there. And, because it is only sold as a medical marijuana product in Colorado, people have to be Colorado residents to obtain it.

Stanley said his brothers are working on manufacturing the oil from low-THC plants classified as hemp — thus allowing it to be produced outside of Colorado's complicated medical marijuana system. But, even if that works, Stanley said he hopes CBD laws won't be the end of the marijuana debate in states that adopt them.

"I'm not one of these guys who wants just CBD-only laws," he said. "But it's an opening. It's a start."

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold