Editors at National Review ponder the significance of insurance giant Aetna’s decision to drop out of Affordable Care Act health coverage.

When the cynically misnamed Affordable Care Act was passed, Democrats and their media megaphones assured the American public that this was a carefully crafted piece of policy architecture, each piece fitting just so with the rest to form a highly functional whole. The planners knew what they were doing, and everything would be fine. Many conservative critics argued that the problem with America’s health-care system was not that it wasn’t centrally controlled enough but that it was too controlled — lacking the makings of a working market and so horrendously inefficient — and that the new law would make that worse.

Time would tell, and now it is telling — with predictable results highlighted by this week’s decision by Aetna to stop offering individual insurance plans through the Obamacare exchanges in most of the locations where it had been selling them. Aetna says that the Obamacare insurance pool is older and sicker than expected, which means much higher costs. Even as insurance premiums soar, Aetna is losing money on most of its individual plans under Obamacare, and so it will join dozens of other insurers in ceasing to sell them.

This is far from the first sign of serious trouble, of course. From the beginning, the administration has had to engage in a series of frantic and legally dubious machinations to keep the system from toppling — creating new rules to let people keep some old insurance plans, delaying and altering various mandates, fines, and requirements, and throwing massive subsidies (at times without any congressional appropriations) at insurers to keep them from bolting.

And yet, here we are. In this third year of implementation, only 40 percent of eligible consumers are buying Obamacare exchange plans, the increase in the insured population has been about 25 percent lower than the Congressional Budget Office predicted when the law passed, and the average cost of subsidizing people in the exchanges is almost 20 percent higher than CBO predicted just a year ago.