My position that laws on mind altering substances should consistently reflect the reality of those substances, is no more "abstract" than your deference to an "experience and settled judgment" that you admit includes past ludicrous stereotypes.
You see a simple majority opinion in favor of marijuana legalization as authoritative.
No, that's just the latest of your many mischaracterizations of my argument. I raised the point about public opinion simply in order to show that YOUR criterion of what "most American adults from the 1970s onward got to know about marijuana from using it or having friends or family who used it" favors MY position. That's what happens when you make up your "principles" as you go along: you wind up rebutting your own position.
You assert, dogmatically, that because alcohol is also awful but legal, so also should marijuana be legal.
Yet another mischaracterization from you. My position is the common-sense one that comparably hazardous products merit comparable legal restrictions; if you were taking the position (as a few on FR have) that alcohol should also be illegal, we'd have agreed on the aforementioned common sense ... but you reject common sense here.
I have to ask: what evidence or point of argument might convince you to oppose marijuana legalization?
If somehow it was shown that marijuana use in and of itself regularly posed a clear and present danger to people other than the user - against all the evidence to date that shows no such thing - then I would find the case for legalization very much weaker. Although criminalization's providing substantial means and motive for criminal violence would remain a point against it.