The failed Republican effort to kill Obamacare had a saving grace. It’s small but significant. We now know the chief cause of skyrocketing health-insurance premiums since Obamacare was activated in 2013. And it’s not the “essential benefits” everyone is forced to buy, though they’ve often been blamed.

The culprits—guaranteed issue and community rating—are more prosaic. They happen to be two of the more popular provisions of Obamacare. Together they drive up premiums nearly 10 times as much as essential benefits do.