The Census Bureau report on health insurance in 2013 shows that on the eve of the Patient Protection and Affordable Care Act, whether you had coverage was largely a question of how much money you made:

PPACA can't fix all of that. Just two-thirds of adults who were eligible for Medicaid in 2009-2010 signed up, according to a 2012 study from the Urban Institute, and even with the law's individual mandate there will still be some people who don't enroll. The same goes for the state insurance exchanges, whose subsidies will draw in some — but not all — of the uninsured in higher income brackets.

But the chart above is still one of the best possible arguments for the necessity of PPACA, by demonstrating that the government programs preceding the law are too narrow to cover the poor. It shows that even with the existence of Medicaid, the Children's Health Insurance Program and other assistance, health coverage in the U.S. remains a luxury good — one that the rich can afford but others struggle, in proportion to their income, to obtain.