The Supreme Court building. (Andrew Harrer/Bloomberg)

We already know that a ruling against the Obama administration in King v. Burwell, this year’s Affordable Care Act Supreme Court case, would be a public health disaster: Millions of people would lose insurance coverage, and insurance markets across the country would stumble out of balance. But what would happen to children, a vulnerable group with specific health-care needs that any rational society would address? The nonpartisan Urban Institute released an analysis Tuesday that games out the possibilities. The bottom line: In a worst-case scenario, a whopping 3.3 million more kids could end up without health coverage.

On its own, a Supreme Court ruling hostile to the Obama administration would result in 730,000 more uninsured children, because their parents would lose the ability to claim federal health insurance subsidies. But such a ruling would also magnify the negative effects of other potential changes in children’s health care, which could result in a lot more pain, particularly for one bracket of low- and middle-income families.

The court will rule this year in the context of a larger debate about the federal government’s childhood health programs. By September, Congress must renew funding for the key Children’s Health Insurance Program, also known as CHIP, otherwise states will have to taper or shut their CHIP programs. As many as 1.1 million children could lose coverage if Congress fails to provide more money. Lawmakers might also relax rules requiring states to maintain Medicaid coverage levels for some low-income children. Doing that, too, would increase the number of additional uninsured kids to 2 million.

If the court struck down Obamacare insurance subsidies in the majority of states, its ruling would make these consequences worse, because some families wouldn’t be able to seek affordable coverage in Obamacare’s private insurance marketplaces, either. With negative effects stacking on top of one another, the number of additional uninsured children would be 3.3 million, and the children’s uninsurance rate would jump from 3.6 percent under current policy to a sad 7.8 percent.

Because of certain program rules, the effects would be particularly bad for children in families between 138 and 200 percent of the federal poverty line, which equates to a yearly income between $33,465 and $48,500 for a family of four. Their uninsurance rate could shoot from 5.4 percent to 27.3 percent.

True, the Urban Institute’s researchers modeled a worst-case scenario. A ruling against the Obama administration in June could adjust Congress’s thinking about what to do on CHIP and Medicaid in September. Senior Republicans also seem keen to cut, not eliminate, CHIP funding this year. But Urban’s analysis suggests that the court could nevertheless exacerbate the negative effects of funding cuts, too.

The court must interpret laws according to more than just its preferred policy outcomes. But no one — not the justices, not the Obama administration’s critics and certainly not anyone concerned with children’s health — should prefer the future that the Urban Institute projects.