An unprecedented D.C. government program will require medical marijuana dispensaries to put aside 2 percent of their profits in order to subsidize pot purchases for poor patients. Under the proposed rule, which was published in the D.C. Register last week and is in the midst of a 30-day review period, dispensaries will give at least a 20 percent discount on marijuana to low-income people at or below 200 percent of the federal poverty level. Clinics often offer discounts to poor patients, and other states mention low-income provisions in medical marijuana legislation. But Allen St. Pierre, executive director of the National...