Jose Martinez, a former Army gunner whose right arm and both legs were blown off by a roadside bomb in Afghanistan, has a new calling: He's become one of the most effective lobbyists in a campaign to legalize the therapeutic use of psychedelic drugs across the country. On a Zoom call ... with Connie Leyva, a Democratic legislator in California who has long opposed relaxing drug laws, Mr. Martinez told her how psilocybin, the psychoactive ingredient in "magic" mushrooms, had helped to finally quell the physical pain and suicidal thoughts that had tormented him. Ms. Leyva says she changed her mind even before the call ended, and she later voted yes on the bill, which is expected to become law early next year. In the two years since Oregon, Washington, D.C., and a half-dozen municipalities decriminalized psilocybin, vets have become leading advocates in the drive to legalize psychedelic medicine, which they credit with helping ease the post-traumatic stress, anxiety and depression that are often tied to their experiences in the military. The campaign has been propelled by the epidemic of suicides among veterans ... but also by the national reckoning over the mass incarceration of people on drug charges. More than 30,000 service members have taken their own lives in the years since Sept. 11 four times the number of those who died on the battlefield. "I will not be told no on something that prevents human beings from killing themselves," Mr. Martinez said.