Flanked by a kid wearing a “420 Autism” tee, on Tuesday Colorado Governor Jared Polis signed into effect House Bill 1028, which legalizes medical marijuana treatment for autism. “OK kids, that’s how we make a law,” he told the families and advocates who had gathered for the occasion.

But in fact, the story of this bill was much more complex than Polis’ pen flourish. A similar bill passed both the House and Senate last year, but was rejected by then-Governor John Hickenlooper, who was not convinced that scientific data existed that backed up the legislation’s application to young people living with autism. “I haven’t found a pediatrician yet who thinks it’s a good idea to sign this bill,” Hickenlooper commented at the time, adding that certain autism groups’ silence on the bill “speaks volumes.”

A study ordered by Hickenlooper on the effects of cannabis on childhood autism has not yet reached a conclusion, though it has put together a working group of parents and health care professionals to advise its process.

Polis has been an opponent of Hickenlooper’s distrust for marijuana’s effect on autistic kids for some time, even running for the office on the platform that he would have signed the legislation into law.

The fact of the matter is that many Colorado families were already treating their children’s condition with medical marijuana. And despite Hickenlooper’s professed ignorance, studies do exist to reinforce their beliefs that the drug can reduce many of the health condition’s more severe symptoms. In Israel and Chile, research turned up positive effects in many clinical study participants, and the U.S. Department of Defense is set to begin a major study on the topic starting in June.

Many states have made allowances in existing medical marijuana regulation for patients with autism. In October, Rhode Island’s Department of Health okay’d the treatment, and last December in Iowa, the Board of Medicine has voted to add autism to the list of qualifying conditions for the medical cannabis program.

Though the governor’s approval was all but guaranteed in the matter, that doesn’t mean that HB 1028 did not face challenges in its lawmaking process. Arguments over how kids would access cannabis recommendations stalled the bill at the end of January, having already gone through two House readings. After negotiation, the legislation passed the House unanimously on February 7.

Central to the hold-up was the question of who was qualified to say that a child would benefit from medical marijuana treatment. Parents argued that many pediatricians were loathe to recommend the drug. Eventually an amendment was added to the bill that stipulates that a kid needs recommendations from two physicians — one to diagnose a condition and one to recommend medical marijuana.

The road to medical marijuana treatment for autistic individuals was a long one, but some Colorado advocates say the delay helped to improve the legislation. “This path happened for a reason,” Michelle Walker of Mothers Advocating Medical Marijuana For Autism told Colorado publication Westword. “Because with 1028, we were able to ensure that individuals with autism and autistic people would have access, whereas the previous program created would have restricted access. Now, we’ve expanded access.”