If governors opt their states out of the health law's Medicaid expansion — as many are now threatening to do — it's the poorest Americans who would find themselves getting the rawest deal.

This set of charts from our graphics department helps explain why: People who earn less than 100 percent of the Federal Poverty Line (about $11,170 for an individual) are ineligible for tax credits to purchase health insurance. In a state like Arkansas, for example, that could be a big deal:

Anyone in the orange area above is stuck in a sort of no-man's land: They're both ineligible for tax subsidies but not covered under their state's current Medicaid program.

Update: Aaron Carroll points out that this chart represents how states cover parents. It does not represent state coverage of childless adults. There, benefits tend to be much less widespread: According to Kaiser Family Foundation, only eight states provide Medicaid coverage to adults that do not have children.