After reading through the first 5 pages of this thread and doing alittle research of my own, I think I've read enough to respond.
First off, according to this
article from the Miami Herald dated May 31, 2011, drug testing is performed by "urine, blood or hair samples" and applicants are randomly selected.
Second, per this
article from the Sunshine News dated just today, drug testing only covers TANF applicants not Food Stamp recipients. Both linked articles, including the one in the OP, state that applicants who pass the drug test will be "reimbursed by [Florida] taxpayers", meaning that the applicant pays out-of-pocket for the first and subsequent test should he/she test positive. Reportedly, cost for the drug test range anywhere from $10-45 (avg. $30).
Third, although the parents may test positive for drug use, that doesn't mean the child wouldn't continue to receive TANF benefits. A positive drug test means a 6-month suspension of TANF eligibility for the parent(s). A second positive result equates to a 3-year suspension. Moreover, a state-approved designee (adult surrogate) can be appointed to recieve and distribute TANF benefits to the child(ren) provided such individual also passes a drug test.
Fourth, setting the question over the constitutionality of such testing for the moment, it stands to reason that only those applicants who believe they may have something to hide will not subject themselves to such testing unless, of course, they believe they can beat the test. Considering that such drug testing is random and the applicant is fully aware of what he/she stands to loose - state-spondored benefits - I doubt many people would foolishly subject themselves to such loses especially when they are desperately in need of said benefits. This part is crucial for people to understand. Those who know they're doing wrong seldom will risk getting caught knowing they have something to lose. Of course, as long as the state allows for "surrogates" to step in and the children can still receive benefits I'm sure there will be some people who may very well take the risk. The good news here is all positive applicants get a "mulligan" and can volunteer for drug rehab.
Fifth and it's very important for people to understand this last part, per the Sunshine News article, there are approximatley 50,000 applicants under FL-TANF, whereas, there are atleast 3 million recipients of FL-Food Stamps who, BTW, are not subject to drug testing under the new Florida law. I understand why that is: TANF is now what "welfare" use to be. As such, that's where the "taxpayer money" is because TANF is the monetary component to welfare whereas Food Stamps is not and is more controlled, i.e., bar codes at most major grocery store chains now weed out ineligible food-stuffs from purchases (excuse the pun).
Bottom Line: I can understand the system in place. However, I question its real effectiveness. You can look at the results in two-ways: 1) either the risk of being drug tested and popping positive is too much of a risk for some and they choose not to subject themselve to being tested; or, 2) everyone who was eligible for TANF benefits did, in fact, show up and get tested and the results vindicated TANF applicants as being clean-cut households who just need alittle help. Per the Miami Herald article:
About 233,000 Floridians applied for cash assistance in 2009-10, including 114,000 families, according to DCF statistics.
This month, 93,170 Floridians received cash assistance, a drop of 8.3 percent from a year ago.
Sounds to me the virdict is still out on the success or failure of the program considering the above results were just 1 month in the making. Let's give it some time and see how things shake out over say the next year or so.