Unfortunately, when dealing with government, any programme initially touted as "voluntary" (while marketing it to the sheeple) will not necessarily 'stay' voluntary. An old favorite ploy is to condition local funding (from state or federal programs) upon compliance with 'voluntary' guidelines. One can readily see examples of this in the "planning" arena, as the pro-'Agenda 21' (read 'socialist') crowd seeks to bring recalcitrant local jurisdictions into line with their 'vision'. There are certainly other examples.
In Santa Cruz County (CA) for instance, those wishing to build 'Granny Units' must 'voluntarily' agree to rent controls (otherwise illegal under state law[Costa-Hawkings Act] and also considered a regulatory 'taking' under the Fifth Amendment of the U.S. Constitution by many) in order to obtain permits. Further, if the proposed structure is considered 'non-habitable' (read 'garage', 'barn', etc.), individuals seeking permits must 'voluntarily' record permanent deed restrictions, prior to permits being issued, granting perpetual property access to county employees, (...without county employees ever having to deal with any notice requirements, nor any of those pesky 'warrants', or 'probable cause' issues supposedly guaranteed to all citizens by the Fourth Amendment to the U.S. Constitution, of course.), and agreeing to pay all costs and 'enforcement fees'(investigative, legal, etc.), regardless of the property owner's ultimately determined guilt or innocence, if, and whenever, county employees, in their sole discretion, might 'determine' that some 'investigation' or other 'enforcement action' is deemed 'necessary' (another Fifth Amendment issue). This is ALL totally 'voluntary' of course... as long as one does not wish to obtain the necessary permits. (!!!)
RE: "As for the Fifth Amendment, it does not stretch as far as you suppose. The Supreme Court has held that routine drug testing can usually be required as a condition of employment and that the police can even require a blood test incident to a DUI stop."
You are correct, of course. The courts HAVE already reduced or revoked many of American citizens' previous 'rights' under the Constitution's 'Bill of Rights'. (2nd, 4th, 5th, to name but a few.) Such reductions and revocations are ongoing, and continue because activist courts are continually busily 'amending' (the "living document") rather than 'interpreting' the U.S. Constitution as it was written and, some would say, 'as intended'. (Can you say "Ninth Circus"...?)
RE: "There is no "slippery slope" here. To go from voluntary testing for environmental contaminants to indiscriminate mass compulsory testing for illegal drugs would be like falling up a staircase."
I absolutely disagree. The 'slope' is always 'slippery' for citizens in their attempts to limit (hold the line) on government powers. There is ALWAYS some excuse, some 'chicken-little' 'emergency' from which the government 'must protect the people', which government uses as an excuse to ever enhance, never reduce, its powers. Rather than 'falling up a staircase', I would suggest to you that a more appropriate comparison might be to "Where does a 500lb gorilla sleep...???", or to "What always happens right after your camel gets his nose under your tent...???"
No real surprise here - It is, of course, a natural, and totally anticipated, thing for governments to always strive to expand their powers over their citizens. It is also true that the more power government has, the less freedom its citizens have. It should therefore ALSO come as no surprise to you either that *some* of us should wish restrain the inexorable growth of government power to the small extent we can, so that we may (at least for the short time we may have left on this planet) cherish for just a little longer, those few freedoms we still have remaining.
Senator Ortiz is, of course, known to many Californians as a staunch advocate of the in-your-face 'nanny state', and we tend to remember some of the more outrageous of her earlier proposed big-government 'solutions'.
...all just my opinion, of course. <;-}
"Individual rights are the means of subordinating society to moral law. ...When ‘the common good’ of a society is regarded as something apart from and superior to the individual good of its members, it means that the good of some men takes precedence over the good of others, with those others consigned to the status of sacrificial animals. "--Ayn Rand
