It wouldn’t have to be the entire state of California. Just LA and SF. While we are at it let Portland and Seattle go, too, but not the rural areas of Oregon and Washington. Let’s see: Chicago, Detroit, Cleveland, New York, Philadelphia, all of Massachusetts and Burlington, Vermont could be kicked out. That would leave south Florida and I’ll bet a bunch of Yankees could be persuaded to go HOME if the proper incentive were offered.
If the constant inflow of retirees from New York and New Jersey were cut off for 20 years, much of the problem in South Florida would die off.