The reason it will never end is because that $7.7 billion pays a lot of salaries in the law enforcement and prison industries.
bingo!
When alcohol prohibition was repealed, guess where the 'revenuers" went - BATFE. Perhaps what we need is a diversionary strategy (post cannabis prohibition) to get the surplus LEOs into the Border Patrol. They stay employed doing something that is actually useful, and we get our freedom back.