When Congressional Budget Office Director Douglas Elmendorf appeared before the House Budget Committee on Wednesday, there were plenty of lawmakers, Republican and Democrat, who wanted to make points about Obamacare. Republicans stressed the CBO's finding that Obamacare will create such a sharp disincentive to work that Americans will stop working to the tune of 2.5 million full-time jobs. Democrats tried to cast doubt on the number or, alternately, to suggest that Americans leaving the work force because they no longer need a job to secure health coverage would be a good thing.

The points had been pretty much exhausted by the time Republican Rep. Diane Black got her turn to address Elmendorf. Her question was straightforward: "What effect [will] the reduced labor force participation have on the economy?"

Elmendorf's answer was simple, short, and devastating. "It is the central factor in slowing economic growth," he said. "After we get out of this current downturn, but later in this decade and beyond, the principal reason why we think the economic growth will be less than it was for most of my lifetime will be a slower rate of growth by the labor force."

Put aside all the talking points about Americans being "liberated" to pursue their interests without having to worry about employer-provided health coverage. Everyone knows growth is the key to economic health for the U.S., and Elmendorf said declining labor force participation will be the "central factor" in delaying economic growth. That's a bad thing.

Democrats might interpret Elmendorf's words to mean he was speaking about the entire decline in labor force participation, not just that part caused by Obamacare. Maybe so. And Democrats might stress that Elmendorf wasn't saying there would be no economic growth, only that the growth that occurs will be slowed by declining work force participation. That's true. But the fact is, the CBO sees Obamacare slowing down the key measure of health in the American economy for a long time to come. It's hard to talk around that.