The New York Times has a story up outlining the effects of the Supreme Court ruling on the Affordable Care Act in general, and the Medicaid expansion in particular:

Starting next month, the administration and its allies will conduct a nationwide campaign encouraging Americans to take advantage of new high-quality affordable insurance options. But those options will be unavailable to some of the neediest people in states like Texas, Florida, Kansas, Alabama, Louisiana, Mississippi and Georgia, which are refusing to expand Medicaid. 

More than half of all people without health insurance live in states that are not planning to expand Medicaid. People in those states who have incomes from the poverty level up to four times that amount ($11,490 to $45,960 a year for an individual) can get federal tax credits to subsidize the purchase of private health insurance. But many people below the poverty line will be unable to get tax credits, Medicaid or other help with health insurance.

I want to preface what I am about to say by pointing out the obvious — the ACA is a great thing. I suspect it will go down as the president's greatest achievement and probably the best thing he's done to fight income inequality. 

With that said, if you look at a map of which states are refusing the Medicaid expansion, and then look at this report from the Urban Institute, a troubling (if predictable) trend emerges. Approximately a fifth (about 18 percent) of all people who will remain untouched by the Medicaid expansion are Black. When you start drilling down to the states where those Black people tend to live, it gets worse. In Virginia and North Carolina, 30 percent of those who are going to miss out are Black. In South Carolina and Georgia, the number is around 40 percent. In Louisiana and Mississippi, you are talking about 50 percent of those who would be eligible for the expansion but who will go uncovered.