The initial post is puzzling. The question seems to indicate an assumption that all (most) pot smokers are lefties. Pot is an amazing plant with proven medicinal properties and extensive (thousands of years) of recreational use. Anyone, regardless of politcal beliefs, can benefit from this plant in some way.
Perhaps it is true that the majority of opponents to pot are right-wing, but this does not necessarily inform one about the feelings of all non-left people.
Evidence of this is playing itself out in Canada and some of the States right now. In Canada's case, there is pretty much a 50:50 split in red vs. blue votes. Yet a solid majority agrees that cannabis should be legalized - so it is happening.
This isn't a win for the left. It is a win for everyone who wishes to enjoy cannabis. And there are alot more "non-left" people enjoying cannabis than the OP realizes.