The result is that these Coastal Megalopolises [sic] are increasingly a two-tiered society, with large affluent populations happily contemplating (at least until recently) their rapidly rising housing values, and a large, mostly immigrant working class working at low wages and struggling to move up the economic ladder. The economic divide in New York and Los Angeles is starting to look like the economic divide in Mexico City and São Paulo. ~Michael Barone

On the political implications of this increasingly severe social stratification, I had this to say last year:

Why anyone wants to replicate the splendid “successes” of the Mexican social, economic and political model, I will never fully understand, but the reality that Mexican immigrants will reproduce the society and culture of their old country was entirely foreseeable and was foreseen.  For some folks, the transformation will not be so bad and will make some into a hereditary oligarchic ruling class tucked away in their little enclaves.  That is, at least until homegrown Chavismo comes knocking on their door.

There are two forces at work gradually creating a new oligarch-serf society in certain parts of the country. First, there is the arrival of large numbers of immigrants coming from cultures in which this sort of stratification and the attendant systems of patronage and graft that go with it are all considered normal.  The inherited political culture of these immigrant populations reproduces itself, and the native oligarchs encourage this development because the highly stratified arrangement suits their interests and may even match their own preoccupations with class-driven politics.  Perversely, those most inclined to bang the economic populist drum about income inequality have the most to gain politically from the processes that are encouraging the widening of income inequality in these megalopolitan centers, since the two-tier structure would benefit an oligarchic party doling out largesse to clients in exchange for support.  Second, there is the steady, ongoing departure of the middle-class families that cannot afford to live as the oligarchs do and do not want to live among the serfs, especially if the serfs are from a significantly different culture and/or race.  Call the process “flight of the native.”   

You have the prospect of the coastal megalopoleis becoming extensions of Latin America in terms of social structure quite apart from any cultural or other changes that may be happening, while Middle America becomes ever-more staunchly the bastion of middle-class interests against a coalition of interests of oligarchs and serfs.  This will make the coastal regions even more inaccessible to Republicans, while continuing to strengthen Republicans over time in the middle of the country.  If the megalopoleis, Upper Midwest and coasts are net demographic losers over time, we should continue to see a decrease in the political clout of relatively left-leaning strongholds.  However, as the social transformation on the coasts continues, these areas promise to produce ever more radically leftist politics that will separate these places even more from Middle America.  It seems that it follows that those who do not want there to be two truly starkly opposed Americas should give serious thought to curbing mass immigration.