Politics may play a role but I imagine cost of living is the primary factor. Broadly speaking people are moving out of the northeast and CA because while they are the most desirable places in the country to live the cost of living due to restrictive housing policy has become unsustainable.
For those who already own homes what about restrictive housing policies would cause them to want to move? They may wish to cash in on equity that parallels demand, or they may be forced out by property taxes they could have never imagined would skyrocket as they have with demand.
Generally, people who make money off of investments are heralded as clever, but for many a home isn’t that, it is their home with all the emotional feelings for some that may apply. This kind of attachment is hard for those who have no empathy for such things to comprehend as all feelings can be for the over rational, emotionally stunted.
The answer to this, of course is to have no state property tax with all taxes based on income. This, of course will weigh more heavily on people who pay rent so rents will need to be fixed so as not to scale with demand. Such measures will prevent low income people who have living wages from becoming homeless. The way to prevent millions of people from wanting to live in so called desirable places that they will ruin by massive density is to meet that demand by making everywhere a desirable place to live. This would best be done in my opinion via centers where people can gather easily and then disperse. This would require a revolution in mass transit.