As a child, the Italian writer Ignazio Silone once joked to his father about a ragged prisoner, handcuffed between two policemen, being dragged off to prison. His father didn’t take kindly to such humor, remonstrating: "Never make fun of a man who has been arrested — Never. Why not? Because he can't defend himself, and because he may be innocent. In any case, he is unhappy." The prisoner was probably sick, too.

San Quentin Prison in California (Lucy Nicholson / Reuters)

Most people under the supervision of the criminal justice system are low-income adults without dependents. Few have disabilities that qualify them for federal disability programs. So they are uninsured. That means a lot of ex-offenders are likely to gain Medicaid coverage under the Affordable Care Act.

The question is whether this is a feature or a bug.

To struggling cities and counties, as well as top correctional officers, the answer is easy. Sheriff Tom Dart, responsible for the massive Cook County Jail, told me that Medicaid expansion is a “game-changer,” which offsets punishing mental health and social service cuts of recent years. He can now obtain services for the estimated 2,000 individuals with psychiatric disorders housed in the jail on any given day. Virtually all of these individuals were previously uninsured and will now be covered under Medicaid. Sheriff Lee Baca, responsible for Los Angeles’s similar mammoth facility, uses virtually identical terms in underscoring the importance of expanding Medicaid.

Reps. Fred Upton (R-Mich.) and Joseph Pitts (R-Pa.), however, believe that this is a problem. They have asked the Government Accountability Office to look into these issues. Citing a powerpoint calculation from the Center for Health Care Strategies Upton and Pitts claim that individuals cycling out of jail or prison could account for “up to” 30 percent of new Medicaid recipients.  As Upton and Pitts put things:

“[T] he data reinforce our concern that PPACA diverted the Medicaid program from its original intent to serve the nation’s most vulnerable populations, including children, pregnant women, individuals with disabilities, and low-income seniors…. We must better understand the true cost of expanding the program to any new population and weigh such costs with the competing interests of our nation’s most vulnerable law-abiding citizens.”

There’s some irony to Upton and Pitts’ letter. Both supported Rep. Paul Ryan’s 2011 budget, a strikingly regressive document that combined large tax benefits to wealthy Americans with punishing cuts to Medicaid, nutrition assistance, low-income housing, Pell Grants and other programs that serve our nation’s most vulnerable law-abiding citizens. Pitts also opposed the expansion of CHIP health insurance coverage to children in recent years.

The two congressmen exclude one broad category from their list of Americans who deserve Medicaid support: low-income adults of working age. Liberals generally believe that anyone who is poor should be entitled to health coverage. Conservatives generally do not. The letter from Upton and Pitts puts into sharp relief GOP contentions that this aspect of ACA supports too many among the unworthy poor.

But what about those released jail and prison inmates who might be getting Medicaid? Do we really want to spend large sums of money providing health insurance to this rather unappealing group of people?

I believe we do. This isn’t because criminals or ex-offenders are always the nicest people. I’ve been the victim of some serious crimes, and I can’t say that I would recommend the experience. A few weeks ago, our closest family friend was robbed on her way to church. The guy grabbed her wallet and keys. He also snatched the Bible she was going to teach from in Sunday School.

But jails and prisons are filled with people with serious psychiatric and physical health problems. Not surprisingly, many have substance use or psychiatric disorders. States and localities spend a lot of money on a patchwork system of safety-net care to address these issues. That system has many holes, producing needless suffering and bad outcomes for everyone – including those of us who don’t commit crimes.

The most obvious issues concern infectious diseases. Theodore Hammett’s team ran some startling figures regarding the 1997 American correctional population. More than one-fifth of all Americans living with HIV or AIDS, more than one-third of those with hepatitis C, and 40 percent of those with TB passed through a jail or prison in a given year.

The figures would look a bit different in 2013. But correctional settings remain key sites to address these problems. Similar patterns hold for drug and alcohol disorders. Many of these men and women pass through jail for a few days or weeks. Then they slip through our fingers, undiagnosed, untreated, their needs and their public health challenges left unassisted. Medicaid expansion offers a key opportunity to do better.

Improved access to care would help ex-offenders. It would also help the people closest to them, especially their partners and their children. This would also help the wider community. Is that really so hard to understand?

Related: Our insane health-care system: free health care in prison, nothing afterward

Harold Pollack is the Helen Ross professor at the School of Social Service Administration and co-director of the Crime Lab at the University of Chicago. He is a nonresident fellow of the Century Foundation.