Following up on an earlier post on majority-Asian suburbs, a number of which are located outside Los Angeles, The Atlantic profiles the LA suburb of San Marino which has remained exclusive even as it has a growing Asian population:

In the early Cold War years, San Marino became renowned for its conservative institutions. The far-right John Birch Society established its western headquarters there in 1959. In the 1966 California gubernatorial election, San Marinans cast only 778 votes for Democratic candidate Pat Brown, compared to 6,783 for Republican Ronald Reagan.
During the 1960s, San Marino residents expressed deep concerns about threats to the racial homogeneity of their community. At a 1966 gathering of the San Marino Republican Women’s Club, Republican California State Senate candidate Howard J. Thelin spent the bulk of his speech responding to the “vicious charges” that he “favored and supported the Rumford Act,” a 1963 law prohibiting racial discrimination in sales or rentals of housing…

It wasn’t until the 1980s, however, that San Marino’s Asian population truly exploded. By 1986, the student body at San Marino High School was 36 percent Asian, up from 13.5 percent just five years earlier. The transformation sparked sometimes-violent confrontations between white and Asian students…

In the end, San Marino’s transformation resulted from the felicitous interplay of economics and assimilationist paternalism. Whites hoped that San Marino’s Asians would work to assimilate rapidly into their adopted community by learning to speak English, participating in civic activity, donating to local institutions, and raising behaved, academically elite children. Shared bourgeois values produced a functional relationship between residents and newcomers and relative racial harmony.

A very interesting story of how a suburb changed tremendously demographically but stayed wealthy. According to the Census Bureau, the median household income is nearly $155,000. It sounds like there is now ethnic diversity but little class diversity: the poverty rate in the community is 3.5%. As long as the newcomers were willing to pay good money for houses and act middle/upper-class, there wasn’t enough trouble between old-timers and newcomers to stop the process.