If you adjust incomes for cost of living, the notion of which states are "behind" has much less correlation to political voting patterns. Here's a comparison from the Bureau of Economic Analysis: https://www.fool.com/investing/general/2014/10/05/which-stat...
According to this comparison, after accounting for cost of living the average Arkansas resident has more disposable income than the average Californian. Having lived in both states, I agree with this (but my friends in California can't fathom this).
* Top 25 states 213 D / 52 R
* Bottom 25 states 11 D / 252 R
so it might seem like there's believable evidence that red states are behind and it correlates with political affinity.