I don’t think think all liberals leave blue cities with the intent of drowning red areas, burn its frustrating when you see the idiots calling for invasions of red bastions. Let people live where and how they want if they’re not hurting anyone else.
It's because all the high paying jobs require some sort of intelligence to do so they can't find enough locals in red cities to fill them all and instead out source from blue cities where there aren't enough high paying jobs for everyone.