Many Americans pay more for child care than they do for their mortgages, even though the wages for those who provide the care are among the lowest in the United States. Democrats see the issue as a fundamental market failure and are pushing a plan to bridge the gap with federal subsidies. We went to Greensboro, N.C., to try to understand how big the problem is and to ask whether it is the job of the federal government to solve. Guest: Jason DeParle, a senior writer for The New York Times.