Gov. Rick Scott’s crusade to drug-test cash welfare applicants is turning out to be another thickheaded scheme that’s backfiring on Florida taxpayers.

The biggest beneficiaries are the testing companies that collect $10 to $25 for urine, blood or hair screening, a fee being paid by the state (you and me) whenever the applicant tests clean — currently about 97 percent of the cases.

The law, which easily passed the Legislature this year, was based on the misinformed and condescending premise that welfare recipients are more prone to use illegal drugs than people who are fortunate enough to have jobs.

Statistically, the opposite is true, despite the claims of Scott and Republican legislators who cheered this unnecessary and intrusive law.

The Department of Children and Families reports that since July, when the drug-testing program started, only 2.5 percent of welfare applicants have failed.

By contrast, about 8.9 percent of the general population illegally uses some kind of drug, according to the 2010 National Survey on Drug Use and Health.

This substantial disparity in favor of the unemployed is not an anomaly. Thirteen years ago, the Florida Legislature funded a pilot drug-testing project targeting poor residents who were receiving temporary cash assistance from the state. Of the nearly 8,800 applicants who got screened for drugs, fewer than 4 percent tested positive. That little exercise in class-bashing cost taxpayers about $2.7 million.

Either the governor didn’t know about the earlier study, couldn’t handle the math or just didn’t want to be bothered with the facts.

However, here are some new numbers that even a sixth-grader can understand:

When the law was passed, the DCF said the new drug-screening law would result in about 4,400 tests a month, or 52,800 a year, at a charge of $10 to $25 each.

Applicants initially pay for their own tests, but they’re reimbursed by the state if the results of the drug screens are negative. If the current rate of failure holds steady at a measly 2.5 percent, Florida taxpayers will be on the hook for 97.2 percent of the tests, between $515,000 and $1.27 million annually.

This is not the scenario presented by Scott and others like Rep. Jimmy Smith of Inverness, who justified the law by wrongly implying that welfare recipients have higher drug-use rates than the rest of us. Good luck finding an office building in Tallahassee where only 2.5 percent of the workers smoke pot in their leisure time.

The support for the drug-testing law — and the polls say it’s popular — is based on the reasonable notion that people who are struggling to find a job shouldn’t be spending a dime on dope. Whether you can legislate sobriety or common sense is highly debatable, but the more pressing question is whether such laws are ultimately worth the expense to government.

So far, the state hasn’t offered any figures on how much money we’re “saving” by drug-testing welfare applicants. Each month the number of those seeking cash assistance varies, and the amount of each payment depends on the circumstances and size of the family.

But with such a small percentage of applicants testing positive, the state will be lucky indeed if the amount of denied welfare benefits exceeds the true costs of administering the law, which go well beyond the urine and blood screens.

Taxpayers are also paying the governor’s legal fees to defend a predictable (and winnable) lawsuit challenging the constitutionality of the blanket drug-testing requirement.

A Navy veteran who’s a single father in Orlando, joined by the American Civil Liberties Union, charges that Scott’s law allows “unreasonable and suspicionless searches” because it’s used against all cash welfare applicants, regardless of whether or not they show evidence of drug use.

Not surprisingly, the staff of the Florida House raised a similar concern when the measure was being written. And, not surprisingly, grandstanding lawmakers shrugged it off.

Some judges haven’t been so quick to do so. In Michigan, a drug-testing program aimed at welfare recipients was struck down by a federal court, citing privacy rights in the Fourth Amendment.

Back in 1997, the U.S. Supreme Court likewise relied on the Fourth Amendment when voting 8-1 to nullify a Georgia statute requiring all political candidates to take a drug test.

Here in Florida, Rick Scott’s campaign promise of mass job creation is at least coming true for professional urine samplers. However, in addition to being sued over drug-testing welfare parents, Scott also faces a court fight for ordering random substance screening on thousands of state workers.

Interestingly, the governor’s pee-in-the-cup mandate doesn’t apply to the one bunch that whizzes away more tax dollars than anyone else — the legislators who pass such useless laws.

I say line up all 160 of ’em for a patriotic whiz-fest at the Capitol clinic. You think more than 2.5 percent might test positive? Let’s find out.

And I’ll pay for it out of my own pocket. Seriously.

(Carl Hiaasen is a columnist for the Miami Herald. Readers may write to him at: 1 Herald Plaza, Miami, Fla., 33132.)

(c) 2011, The Miami Herald Distributed by Tribune Media Services Inc.