The Democrats have become the party of the urban gentry, public employees and the government-dependent poor, an identification that hurts them elsewhere.You see, in Kotkin's description of the main Democrat base groups, an outline of the direction in which my native state, CA, is trending. Because of its beauty and climate, CA will continue to have a fourth group - affluent retirees.
These cluster along the coast and in the Sierra foothills, enjoy the scenery and weather, and essentially ignore the Democrat silliness emanating from "Sacra-tomato" as many sarcastically label the state capital. If they maintain residence in CA, many will vote R and certain rural/exurban localities will elect a few Rs to the state legislature - a basically toothless permanent minority.
For a thoroughly dystopian view of CA's future, check out the Matt Damon SF film Elysium. To be sure, it exaggerates for effect but the directionality is spot on. Picturing a future Los Angeles looking like the unpaved slums of Ensenada or Cape Town, it is beyond bleak.