Before the rollout of Obamacare, administration officials repeatedly defined success as making sure that about 39 percent of the projected seven million enrollees on the new exchanges would be composed of young adults. Attracting a critical mass of young and healthy individuals was viewed as necessary to offset the costs associated with forcing insurers to cover older and sicker Americans with pre-existing conditions.

Yet on Jan. 13, the Department of Health and Human Services released preliminary data showing that just 24 percent of Americans signing up for insurance through the exchanges were in the key age group of 18- to 34-year-olds. The news followed a Jan. 9 warning to investors from insurer Humana Inc. that the risk pool of its enrollees on Obamacare’s exchanges was worse than expected. But insurers facing potential losses have one thing going for them: federal taxpayers.