hear me out.
i should begin by stating that i would oppose this policy in the way it is usually presented, which is as a means to deny people access to help. but, this actually isn't on a libertarian basis, it's on a socialist basis. i would argue that drug addiction is a public health issue and that social services should exist to deal with it. not on the cheap, either. it's what government does.
to deny people welfare because they're on drugs is completely absurd. should they go rob a bank instead?
i have somewhat of a hazier view about whether employers should be allowed to test employees. it seems unnecessary to test a fast food worker - you'll be able to figure out fairly quickly whether it's impeding them or not. but it's probably a good idea to test a structural engineer from time to time. i'd reverse the normal logic: the more complex the job is, the more important it is that the person that's doing it is sober when they're working.
elected officials take the issue to the highest level. i think this falls into the category of public accountability.
pissing in a bottle a few times a year is hardly onerous. but, it would help us ensure that our government is being run by people that are clear-minded.