I don't know if I'm up to the task of "exactly" but I'll hit the highlights.
1) I've long advocated either getting serious about the "war on drugs" or giving up, because I believe efforts with our existing half measures are doomed to fail. The one area I strongly disagree with the "czar" about is the issue of punishing the offenders. Frankly, I think testing without consequences amounts to little more than a half-hearted effort that would accomplish next to nothing.
2) Attacking the problem at the source simply isn't enough. Controlling supply is one part of the solution certainly, but reducing demand also has to be a part of any effective interdiction effort. IMO. Taking the user off the streets is part of that.
3)If drugs are found in their system (I'm talking about controlled substances here, not whether they're taking Sudafed for a cold), then I really don't consider them students at that point, they're common criminals, no more no less. And I give a rather significant amount of leeway toward efforts that put criminals out of circulation.
4) re: search and seizure -- I see nothing "unreasonable" about it really, IMO it's a very reasonable response IMO to an existing problem. And one of the more productive ideas I've heard in a while, as it identifies offenders pretty quickly. I'm really not prepared to go into specific detail about how to design a program that's most effective at interdiction, I'd need a roomful of legal experts & law enforcement to work that out anyway, but hopefully it'll suffice to say that I believe there's a way to structure a testing program (with multiple tests for positives) etc that would be worthwhile.
Sorry if this seems vague, I'm not being short with you, I'm just draggin' ass after a long day & got some personal worries on my mind tonight.