Some 13 percent of people who signed up for health-insurance coverage in 2015 under the Affordable Care Act have fallen off the rolls. The Obama administration attributes much of this decline to many people failing to pay their share of premiums. (Some probably got addicted to the “free”  — for them — care in emergency rooms.)

Things could get more exciting soon if the U.S. Supreme Court rules that the Affordable Care Act only authorizes subsidies to help people pay for health insurance in states that established their own health-insurance exchanges. About 6.4 million could lose their premium subsidies if the Supremes rule against the subsidies.