On the campaign trail in Iowa, Hillary Clinton claimed that President Obama’s Affordable Care Act is little different than her health-care plan in 1993. “It was called HillaryCare before it was called ObamaCare,” she told supporters on Jan. 21.

Her timing was awkward. That same day, the Department of Health and Human Services announced that health-insurance premiums on the Affordable Care Act exchanges rose an average of 9% between 2015 and 2016.

...