Pretty much like how all those folks living in New Orleans could have all moved to avoid Hurrican Katrina? Or like all those folks living in <location> could have moved to avoid <social unrest>?
I don't know how many folks here at OCDO have ever seen refugees in person - folks who have made the decision that continuing to live in Place A was so bad that it was worth giving up almost everything you owned and risking the lives of not only yourself but your family to try and find a place where the danger was not quite as immediate and deadly. Refugees do not find a job in another state, sell their house, and settle in to the new neighborhood.
The majority of folks in the USA are not able to just pick up, move, and resume life as they knew it in some new location. If it's not the lack/uncertinty of finding a job, it's the lack of finances to cover the costs of moving. This goes for folks that are labeled as upper-middle-class as well as for those who are labeled as poor. Think about it - how much liquid cash do you have that you could afford to spend and not replace in order to finance picking up and moving?