What you see is exactly the reverse of our cultural mythology: Heading into midterms, Republicans are very much the party of the poor and Democrats are the party of the rich. This seemingly sounds nuts. It isn’t. Thirty-two states have Republican-controlled legislatures.
Eighteen of the 19 poorest states have legislatures where both chambers are Republican controlled. New Mexico (46th richest, fifth poorest) is Democratic. But there isn’t another blue or purple state until you get to purple Maine (31st richest, 20th poorest) with its “split” legislature of one party in each chamber. All the states in between (such as Tennessee and Florida) are Republican, both chambers. So is Michigan, where Republicans hold all high state offices (where Donald Trump won in 2016). Above New Mexico, you jump all the way to middle of the pack Vermont (27th richest, 24th poorest) to find a state with both legislative chambers held by Democrats.
But all five richest states have both legislative chambers controlled by Democrats – Maryland, New Jersey, Hawaii, Massachusetts and Connecticut. Overall, Democrats dominate the 20 richest states.