Here's a breakdown of per capita income in the 50 states. National per capita income is $42,070.
As you can see the majority of the states below the national average have two Republican senators (red line). A purple line means one Republican and one Democrat and a blue line means two Democratic senators. The wealthier states are Democratic.
What about governors?
Well, in the 25 states with per capita income above the national average, 12 (48%) of those states had Republican governors.
However, when you look at the 25 states below the national average, 18 (72%) had Republicans.