The Right says: If drugs are legal, people will shoot up, and society will go to hell.
The Left says: If guns are legal, people will shoot-em up, and society will go to hell.
Word-play aside, other options are possible:
The authoritarians say: People can’t be trusted with either.
The (true) liberals say: We can trust people with both.
Underlying so many of our political debates is a philosophical assessment of human nature.