LOL, you don’t want to go there. Statistics for marijuana show it to be so far safer than alcohol or guns or even aspirin, that you’d be laughed out of the discussion.
But I will tell you where you can argue against marijuana - its effects on the brain development of children. Up to a certain point (late teens, I believe) it has a marked and measurable negative effect on all sorts of mental abilities, with associated negative emotional effects, from apathy to panic attacks.
After the brain reaches physical maturity, those negative effects drop off dramatically. But for kids and teens, marijuana is bad news.
On the other hand, for kids and teens, alcohol is bad news too - equally if not worse.
So there are deeper issues here than yes/no.
I’m kind of a clown, so I don’t mind being laughed at. So at what point does employability become a part of the rubric? If somebody on the job has a BAL and there’s an accident, they need a mighty fine lawyer. Yet they can be rip-roaring drunk the night before, it’s no issue. On the other hand, well, you know wht\at I’m going to say.