In addition, consider the states in which pot is decriminalized or legal for recreational use. California, Oregon, Washington, Nevada, Colorado, Nebraska, Minnesota, Ohio, New York, the New England states excepting New Hampshire and Vermont, Virgina, Alaska, and Mississipi.
Of those, only Alaska and Mississipi are conservative states, and Alaska has a 'high' population of Inuits who smoke the stuff for religious reasons, which skews the state further in favor than it otherwise would be.
Like it or not, pro-weed is firmly in the realm of leftydom...Except our good buddy Ron Paul of course, who favors legalizing it.
We're talking about prohibitionism.
Do some research on the origins of prohibitionism - the thing that got the ban this/ban that attitude really rolling in the 19th and 20th century - and then we can have a discussion on whether that mentality is a progressive or conservative cause.