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 would lose insurance coverage, and insurance markets across the country would fall out of balance. But what would happen to children? The nonpartisan Urban Institute released an analysis this week that games out the possibilities. The bottom line: In a worst-case scenario, a whopping 3.3 million more kids could end up without 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 no longer get federal health insurance subsidies. But such a ruling would also magnify the negative effects of other potential changes in children's health care.

The court will rule 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, or states will have to taper or shut their 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.

CartoonDavies' latest cartoon: Nassau's got mailCommentSubmit your letterReader essaysGet published in Newsday

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

The effects would be particularly bad for children in families between 138 and 200 percent of the federal poverty line (between $33,465 and $48,500 for a family of four). Their uninsurance rate could shoot from 5.4 to 27.3 percent.

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

advertisement | advertise on newsday

The court must interpret laws according to more than just its preferred policy outcomes. But no one should prefer the future that the Urban Institute projects.

Stephen Stromberg is a Washington Post editorial writer. He specializes in domestic policy, including energy, the environment, legal affairs and public health.