This is a pretty good take, though I would personally expect some of the poorer Southern states to be more amicable to Medicaid expansion - I don't know the region very well though.
Many Southerners are opposed to Medicaid expansion, even when lower income -- part of a good bit of more traditional conservatism and opposition to government control. Sometimes a lot of this is regional -- one of the most interesting things I saw looking at the data was that Nebraska and Utah had the same Medicaid expansion margins, even though Utah is much more Republican. Generally speaking, Southern Whites are even more conservative and inelastic than Nebraskans, so I applied the same general logic there, but marking off states like AR that have a hint of economic liberalism too them and states like GA that are somewhat purplish.
