Wisconsin Gov. Scott Walker (fun fact: he once ran for president) is a policy innovator with fresh ideas. Which is why he proposed this week that recipients of Medicaid, the program that provides health insurance to poor Americans and nursing care to the elderly, should have to get drug tested before they're allowed to receive the benefit.

Is there an epidemic of drug use among Medicaid recipients? Well, no. There's zero evidence that it's a problem at all. And while drug testing has never been forced on Medicaid recipients before, some states have drug tested welfare recipients. Those programs have been failures, proving only that welfare recipients seem to use drugs at a lower rate than the population at large.

But it doesn't really matter how many people you catch, defenders of drug testing say. This is about sending a message: You're not going to get a government benefit if you use drugs. You want the government to give you a hand? Then you'll have to prove that your bodily fluids are pure.

Which is why I propose that we extend this principle even wider than Gov. Walker suggests. There are millions of moochers sucking off the government teat, getting benefits they didn't earn, and at the very least they ought to show they aren't using the money they get to go out and feed their disgusting habit. So we ought to drug test them too.

I speak, of course, of the millions of Americans benefiting from the mortgage interest tax deduction.

Drug testing recipients of the mortgage interest deduction (I'll call it the MID from this point on) probably strikes you as ludicrous. But why is it stranger than forcing welfare recipients to pee into a cup while a bored bureaucrat stands outside the stall? Might it be because we have different assumptions about the moral worth of those who get each benefit — and therefore what degree of humiliation it might be reasonable to subject them to?

Just the other day, I had an experience you may have shared: Filling out my family's taxes, I entered our mortgage interest and saw the "Amount you owe" in the corner of the screen on my tax software click satisfyingly down. Like anyone else, I'm happy to take the deduction as long as it's there. But make no mistake: This is a giant giveaway to the middle class, yes, but mostly the rich, for two reasons. First, if you have a bigger mortgage, you pay more in interest and thus are able to deduct more. And second, because taxes are progressive, any deduction is worth more to people who have higher incomes, because they're paying taxes at a higher rate.

Which is why most of the MID's largesse goes to people who are well-off: According to the Tax Policy Center, 72.5 percent of the benefits went to people in the top 20 percent of incomes last year. The average MID benefit to people in the top 1 percent was a healthy $10,000.

Now ... I don't really think all homeowners should have to be drug tested to get the MID. Nor should people on welfare or Medicaid, and nor for that matter should workers, except in some very narrow circumstances where they have other people's lives in their hands. Almost no one should be drug tested, whether because they're getting government benefits or for any other reason.

But ask yourself: Why does it sound so crazy? And why is it that someone like Scott Walker would never consider drug-testing homeowners, not even for a moment, when there are certain people he's so eager to drug test?

Lots of people don't see the MID as something akin to Medicaid or food stamps. "How is it a handout," they say, "if the government is just letting me keep more of my money?" But it most certainly is a handout. The government took the taxes you were supposed to pay, and then gave some of them back to you. It essentially wrote you a check to pay part of your mortgage, for no reason other than that you're a homeowner. You're no different from the person who gets Section 8 vouchers to help pay for their housing, except for the fact that you don't really need it.

Many of us see some government benefits as deserved and some as undeserved, not based on the nature of the benefit but on who's getting them. These false distinctions are enabled by what political scientist Suzanne Mettler calls the "submerged state," a plethora of government benefits and programs that most of us manage to convince ourselves have nothing to do with government at all, so long as we're the ones reaping the rewards. In surveys she conducted, people who had availed themselves of things like Social Security, Medicare, and Pell Grants nevertheless insisted that they had never used a government program.

But government does thousands of things that most people don't think of as government, until they might get taken away. That's why people reacted with such horror to the recent budget proposal the Trump administration released, when it threatened to eliminate Meals on Wheels, afterschool programs for kids, and the EnergyStar program.

So the next time you hear a politician talk about people who should be forced to jump through bureaucratic loopholes or even endure humiliation because of a government benefit they're getting, consider all the government beneficiaries who don't have to do such things. Including yourself.