Not sure whether it is so much blue states vs. red states, micro ... but, I strongly suspect that the vast majority of the underwater defined benefit pensions are for government employees, rather than private business employees. For decades and decades and decades, the public employee unions spend an enormous amount of their dues to elect Democrat politicians who they can then "negotiate" with to procure retirement benefits that nobody in their right mind would ever agree to, otherwise.

The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence