Anyone who thinks MJ is the gateway drug has never tried to stop smoking. How many users of MJ or harder drugs have you ever seen who did not start with cigarettes and/or booze. I have known alcoholics who also used MJ, and while sometimes nasty on booze, they never were on MJ.
In Washington, DC it was found that over 90% of all MJ arrests were of black people although about half of users were white. Also it was found that 2 1/2 times as many youth were arrested for MJ as were graduating from high school. So last November, 70% of voters approved a referendum supporting legalization of marijuana. Republicans in Congress have forbade DC to implement any laws on this legalization. Thus, although certain rules were spelled out in the voted referendum and are being followed, the DC government cannot approve any laws to tax or otherwise regulate MJ except for what the referendum approved. No wonder the 650,000 people of DC want to be a state. Can you imagine Republicans in Congress telling the smaller populations in Wyoming or Vermont that kind of BS?
Having worked in the field, ANY substance of abuse is a gateway drug. The population of DC should consist of elected officials (IOW, in state-owned housing) and foreign nationals residing in embassies, and no one else.