I wouldn't be surprised if the ACLU wins this one, either, and it's not all that ridiculous. The argument is a Constitutional one, against unreasonable search and seizure, the right to privacy, self-incrimination, and in having to prove your innocence.
Having people on welfare drug tested sounds like a really good and reasonable idea, but there is simply no way to implement it without trampling on people's rights, including those who never do drugs. And I've never seen the government shy away from trampling on a right when they think they can get away with it.
Urinalysis reveals not only the presence of illegal drugs, but also the presence of perfectly legal drugs administered for medical conditions. It also reveals the existence of many other physical and medical conditions, like pregnancy, and genetic predisposition to disease. In 1988, the Washington, D.C. Police Department admitted it used urine samples collected for drug tests to screen female employees for pregnancy, without their knowledge or consent. Naaaa, that's not an invasion of privacy at all. <snort>
Drug testing laws are all about balancing the employer's business need for the test against the employee's right to privacy. The stronger interest prevails. Even if the employee shows that his or her reasonable expectation of privacy has been infringed upon by the testing, drug testing is still lawful if the employer can demonstrate that its legitimate business need for the test outweighs the employee's privacy rights. The employer is on strongest ground when the employee's job deals with the safety or security of others, or when it has a reasonable suspicion that the employee is using drugs at work. On the other hand, employers' needs are considered weaker when these factors do not apply, especially if the test is administered without notice or in a particularly intrusive manner.
"You're poor, so we think you are on drugs. Now you have to prove to us that you're not on drugs." There's simply no way that's gonna fly with an employer because it lacks a safety or other legitimate business need. It especially won't fly when it is THE STATE trying to pull something like that.
The Constitution applies to everybody, whether you like them or not. As bad as it is when liberals want to dispense with some or all of the Constitution to suit their wants and desires, no matter how fiercely they try to defend doing so, it's just as bad when conservatives do the same thing, maybe even worse, since many conservative routinely like to bash people over the head with the Constitution. You can't pick and choose which parts of the Constitution you want to selectively apply to people.