I have pretty much no sympathy for pot use, but how many mass shootings have there been in Manhattan that were committed by potheads? Pot use causes problems that are real, but do we need to go full-on Reefer Madness 2.0?
How about Chicago? Or Indianapolis? Or Baltimore? Milwaukee? I'll bet pot use is extremely high in those places with incredible amounts of homicides per capita.
Ever watch Live PD or some of those other live cop shows? How many times is marijuana found in cars with people with rap sheets? Quite a bit.
Again, does correlation mean causation? Maybe, maybe not.
But let's not casually dismiss the argument.
Again, going back fifty years when mass shootings were much rarer, pot use among white males was still pretty small. That's changed. And the pot today is much stronger than the pot from fifty years ago.