Today, John Hood writes another column I recommend you read, print, laminate, and post on your refrigerator. ObamaCare, as we’ve been told repeatedly by its supporters, will lower health care costs by reducing reliance on high-cost emergency-room care by the uninsured, who will be enrolled in Medicaid.

Nope. From Hood (emphasis is mine):

More importantly, to assume that growth in emergency-room visits was an artifact of growth in the uninsured population is to do just that – make an assumption, without good evidence. As some analysts have long pointed out, patients with insurance are more numerous and make up a majority of the people crowding into emergency rooms.

The new study, by a researcher at the University of California at San Francisco, underlines a fact even more inconvenient for ObamaCare supporters. Not only are insured patients the majority in ERs, but patients insured under Medicaid are twice as likely to use ERs as the uninsured are. In North Carolina, 24 percent of ER patients are on Medicaid, far higher than the 14 percent of North Carolinians who are enrolled in the program.

Why is this significant? Because the main way ObamaCare is expected to reduce the ranks of the uninsured is by enrolling them in Medicaid. Far from reducing ER use, ObamaCare will likely increase it.