CHRISTOPHER BOOKER:

Like 81 percent of Obamacare enrollees nationwide, the cost of their plans was offset by federal government subsides determined by their income.

As recently as last year, Alabama residents enrolled in Obamacare had three providers to choose from – Humana, UnitedHealthcare and Blue Cross Blue Shield. But this year only Blue Cross remained, and it already controlled more than 90 percent of Alabama's private insurance market.

Both UnitedHealthcare and Humana, cited the high costs of individuals enrolled in the marketplace as the reason for their departure.