It is the hollowing of the middle, the poor will stay for the welfare, the rich will use their Nevada Incorporated Tax jiggle to stay around.

Exactly this. I've got anecdata from people who have left because they can't afford housing, to retirement age people who are cashing in on their real estate and moving somewhere cheap, to conservatives moving to a more conservative state.

The only _kind of_ real data point in this article is that the last item (politics) makes for 1/3 of the people leaving.