Uh, you haven't been to any college campi lately, have you? Virtually any drug you're looking for is easily available.
And BTW, it's telling that you make alcohol out to be LESS DANGEROUS than illegal drugs. Fact is, if you could transition a college campus off of alcohol to marijuana, or even cocaine, you'd see a lot less chaos and destruction on campus.
Your argument should be: "Kids can't handle their alcohol -- let's BRING BACK PROHIBITION!"
Alcyhol is the by far the most used and easily available. If you switched it with pot, it would be a mellow party. If you switched in X, DJ Dan would be a lot richer. If you switched in cocaine, well, I would be more concerned. PCP, same way. Heroine, everyone would be laid out, but none of them would be at college in the first place.
For some reason, beer just fits perfectly.
I will fight to by dying breath the foces which try to drag this American society down into becoming a cesspool of drug-addled shambing wrecks.