YA THINK? ObamaCare’s Prognosis Grows Dimmer.

A nightmare for Affordable Care Act supporters has been the possibility that only the sick would be left to purchase insurance through its exchanges, driving premiums up and insurers out. While the law’s boosters have been quick to dismiss the possibility that such a so-called death spiral could occur, data published in the Wall Street Journal suggest that this chain of events may not be so far-fetched after all.

The findings are significant not just for what they say about how Obamacare is working now, but also for their impact on the political debate over its future.

At its base, the data show that people insured through the law’s exchanges have higher rates of serious medical conditions. Of the enrollees who have seen a doctor or other health-care provider in the first quarter of this year, 27 percent have significant medical problems, including diabetes, cancer, heart trouble and psychiatric conditions. That rate is substantially higher than that for patients in nonexchange market plans over the same period. And it’s more than double the rate of those who were able to hold onto their existing individual market insurance plans after President Barack Obama was forced to allow them to keep them.

This outcome should not surprise anyone. The law’s one-size-fits-all regulatory regime, which requires insurers to offer coverage to all comers and prohibits pricing of coverage based on an applicant’s health status, was bound to increase the number of relatively sicker people purchasing insurance through the exchanges. Moreover, Obama’s executive action, which effectively allowed many people who had individual market plans to remain in them through at least 2016, bifurcated the insurance markets such that healthier people remained in the plans they already had, while relatively sicker patients were left to acquire coverage through the Affordable Care Act’s exchanges.

Related: Why ObamaCare Can’t Be “Fixed.”