Proponents first extolled the “medical” benefits of marijuana. They convinced voters to bypass the Food and Drug Administration, substituting popular vote for research, clinical trials and science. They downplayed the harmful health effects and never mentioned that FDA-approved medical marijuana for cancer patients is already legally available in nabilone pills. Ads showing seniors toking to relieve the effects of chemotherapy tugged at heartstrings. Yet in Arizona, fewer than 3 percent of marijuana cardholders have cancer. Statistics suggest “medical” marijuana is a ruse for recreational pot: Cardholders are predominantly male, one-fourth are under 30 and 83 percent use it to relieve self-defined “chronic pain.”