From the Washington Post:
When the U.S. economy slowed during the recession, so did one of the major demographic shifts of the last several decades. For a brief respite, the Northeast and Midwest stopped shedding quite so many residents to the burgeoning Sun Belt. That trend, though — which has big consequences for politics, among other things — has been picking back up.
New census data shows the trend accelerating back to its pre-recession pace. Florida, which actually lost more domestic movers than it gained right after the housing bubble burst, picked up about 200,000 net new movers between 2014 and 2015 (this number includes people who move between states, not immigration into the United States from abroad). Illinois, meanwhile, had a net loss of about 105,000 residents, its largest one-year population leak in the 21st century.
Note: Does not include immigration (legal or illegal) into the USA.