Not surprisingly, the San Francisco area is popular with people who don’t need a big backyard for their kids, such as homosexuals and childless couples, while North Texas attracts families from across America. San Francisco is very Democratic, while the Metroplex is quite Republican.
Why? The simplest explanation is that GOP “family values” resound more in states where people can more afford to have families. In parts of the country where “Families can be easily supported, more Persons marry, and earlier in Life.” And where it is economical to buy a house with a yard in a neighborhood with a decent public school, you will generally find more conservatives. It’s a stereotype that marriage, mortgage, and kids make people more conservative, but, like most stereotypes, it’s reasonably true. You’ll find fewer Republicans in places where family formation is expensive. Where fewer people can form families, Republican candidates making speeches about family values just sound irrelevant or irritating.
The arrow of causality points in both directions. Some family-oriented people move to more affordable states in order to marry and have children, while people uninterested in marriage and children move in the opposite direction to enjoy adult lifestyles. This population swapping just makes the electorate more divided by geography rather than tipping the national balance toward one party.
Interesting sociological question.