That might work to keep minority behavior (e.g., heroin or meth use) in the minority - but with over 40% of Americans having used pot in their lives and over 50% favoring legalization, that particular flavor of toothpaste is well out of the tube.
A January 2014 CBS poll does, indeed, show a bare majority of Americans--51 percent--in favor of our legalizing marijuana. This is a bit less than the 58 percent shown in a slightly earlier poll, by Gallup, conducted in October 2013.
But I am not at all sure that this slight preference is irreversible. In fact, the trend seems to be going in the other direction.
In any case, if the instructive impact of the law "work[s] to keep minority behavior (e.g., heroin or meth use) in the minority," as you have posited, that would be a very good thing, I believe.