So this whole issue of making people who receive welfare take drug tests is making the rounds on facebook. I feel like this is pretty idiotic on it's face, but it seems to be popular enough that maybe it's worth my while to explain what exactly is wrong with it.
First of all, let's start off with what I would suggest is the basic purpose of government welfare payments: there are certain people out there that are failing (justifiably or unjustifiably) at supporting themselves, and the government provides those people with enough resources to maintain a very basic standard of living.
If you accept that, then you also accept that suggesting that someone's welfare should be taken away, for any reason, is suggesting that that person should no longer be given the resources to maintain a very basic standard of living. (Except for the very obvious exception where a person's welfare payments are generally discontinued when they are replaced by a job or other source of income that allows for a better standard of living).
People aren't going to just shrug and accept that as their fate...they are going to pursue other ways of obtaining those resources. And in the modern world, practically all of the non-employment, non-government welfare ways of obtaining the resources to maintain a very basic standard of living are illegal. Take food, for example. You aren't allowed to steal it, obviously. In most places searching for it in dumpsters is also technically illegal. Lots of places have strict rules about begging. Foraging options are considerably limited by trespassing laws. Shelter is similarly problematic. Breaking into a building to keep warm or dry is obviously illegal. Hanging out in an abandoned building is often illegal too. Hell, in San Francisco sleeping on a public sidewalk is currently illegal. So where exactly are these people supposed to go?
Prison, if you're actually interested in enforcing all of your laws (oddly, fines are not a huge deterrent to people who have been kicked off welfare). And that will cost quite a bit of money. Especially when you consider that a significant portion of the welfare population is mothers with young children. Those children are going to have to go somewhere, either into foster care when their mother loses her house or apartment because we don't tolerate child homelessness in this country (except we do), or into foster care when their mothers go to prison, or into prison themselves when they start stealing food and breaking into buildings to keep warm or dry, if we want to be all Dickensian about it. But, again, we are talking about spending quite a bit of money here. Just for the personal satisfaction of knowing that government welfare has been limited to the "deserving" poor.
I think the real issue, however, is that people suspect that trying to scrape by on the meager amount of resources that government welfare provides isn't quite miserable enough, and this is just one more way to take out some resentment on a group of people they think are getting away with something. I honestly don't really know what the average person on welfare looks like in this country, but I have enough experience with job hunting to realize that not everyone in this country who's willing to work is able to find a job that will pay them.