Whether or not the government says something is OK has very little to do with whether it’s moral. It’s unlikely a guy smoking pot is the only legal but immoral thing you’ll see on the street.
And as for the spiral, remember pot was legal for most of the history of this country. We won some pretty big wars with pot legal.
What was so hard about it was that you could be thrown in jail for the rest of your life for it. The creeping moral failure of liberalism is what decided to make it illegal, liberalism believes in control and making sure you don’t do things they disagree with. Restoring freedom is conservatism.
Ditto.