The problem is we can only get student loans from the govt now. They took over the business. If there was another choice for people who want to do drugs in college then yeah go for it...but it is also not a handout like welfare so I don't see there ever being a big clamor for people to start drug testing college students.But we only want to punish the poor, not middle class or rich.
I would be fine with drug testing anyone that gets gubmint money, college students, farmers, corporate boards, etc.