Also, if you go back say, 10 years, you'll see that most HN threads have very little politics in them, so yes, that has been the norm before.
Correct on the first, wrong on the second. Stockpiling issues doesn't work in U.S. politics: it's how you get primaried.
The truth: there are enough Democrats in competitive districts where legalized marijuana would lose them the next general. It's a majority of the minority problem. Not anything strategic.
They schedule drugs through Article 6 of our Constitution which makes treaties law of the land. Our ability to change drug laws in the US is outsourced to the UN. It's not a "Republican or Democrat" issue specifically. Though, the prison system that is increasingly private which makes money hand over fist on drug users and pushers certainly is an issue either political party could champion and change.
They kind of have done the first part, in effect, “marijuana” and “hemp” being legally distinct, and it being possible to get all the pharmacologically interesting bits for which marijuana is sought in forms that are legally “hemp”.