What’s disengenuous about your point is you’re not identify whom is immigrating and who is emigrating.
You’re argument might have some validity if it wasn’t for the fact that these conservative regions have both been conservative and poor for most of the time our nation has existed.
The primary difference is that the egalitarian nature of the blue states creates a more dynamic opportunity with better utilization of Human Resources, more competition, greater educational attainment, greater entrepreneurship, greater investment in infrastructure (you know? That damned socialism?). It is in these egalitarian values, culture and history where the difference lies.
The conservative social and economic traditions of the red States has trapped these regions in a vicious cycle of poverty and ignorance where they lack the competitiveness and dynamic social and economic nature of the blue regions.
To put it more bluntly for over several hundred years the elite property owning political class in the red regions have promoted racial and social resentments to justify their exploitation and domination of economic resources. This short sightedness to protect their economic privelage with its lack of investment in Human Resources and public infrastructure has created a poverty trap that has existed for over 200 years.