After that war ended, African-American migrants to California were surprised to find racist real-estate redlining and a virulent West Coast version of Jim Crow. Tim Watkins, president of the Watts Labor Community Action Committee in Los Angeles, told me that his father was sent out here alone from Mississippi at age 13 because a lynch mob was after him. “When my father got off a train in L.A., the first thing he saw was a ‘Whites Only’ sign on a restaurant,” Mr. Watkins said. “When he married my mother, a white woman, he could not marry her here, so their marriage certificate is in español because they went down to old Mexico.”

The Civil Rights Act of 1964 helped, but not enough to stop the violent Watts uprising of 1965 or the Rodney King riots of 1992, both of which expressed collective fury over systemic racism. As recently as 1994, Gov. Pete Wilson, a Republican, revived a flagging re-election bid by backing Proposition 187, which barred the state from providing public services to undocumented immigrants. Proposition 187 passed, but was never really implemented. According to Senator de León, Wilson’s re-election did for California what Mr. Trump’s election and promised deportations might yet do for America: It woke up the Latino vote and ushered in the deep-blue politics that have since helped to legalize same-sex marriage, make Obamacare work, turn virtually the entire state into one big sanctuary city for undocumented immigrants and enact far-reaching climate-change regulations.

Anyone who doubts that progressivism is good business has to reckon with the fact that California is now the sixth largest economy in the world, ahead of France, Russia and India, with $2.46 trillion in gross domestic product.

It’s not all sunshine, of course. California’s $54 billion agriculture industry thrives on the exploitation of migrant workers, and our poverty rates and income inequality are among the nation’s worst, thanks partly to a technology economy that makes millionaires in coastal cities but does little for the hinterlands except raise the cost of living. That helps explain why 3.7 million Californians — 33 percent of the vote — chose Donald Trump and why California’s electoral map resembles the national one, with red counties in the rural white interior and blue mostly on the coast.

Many Californians are also casting a gimlet eye at the two big industries whose leaders talk a liberal game but sell products that arguably undermine civil society: entertainment and technology. In Los Angeles, that conversation includes movies and TV shows that, in the words of the actor and author Robinne Lee, “often extend the perception that it’s a white man’s world and everyone else is just a guest star.” In Silicon Valley the obvious culprits are Twitter, which has become a hate-speech superhighway, and Facebook and Google, both of which capture eyeballs by tailoring news feeds and search results to make us feel good. In so doing, and especially by supporting the mass dissemination of fake news and outright lies, they radically reinforce the biases that drive Americans into dangerously oppositional camps of red and blue.

But the overwhelming — and novel — sentiment coming out of Nov. 8 remains one of common identity, which is remarkable in a place that is 38.8 percent Hispanic, 38 percent non-Hispanic white, 14.7 percent Asian and 6.5 percent African-American, and where just about everybody knows both steady churchgoers and at least one loving and stable family with two moms or two dads. Paola Martinez-Montes, director of the Alliance of Californians for Community Empowerment in San Diego, says that California’s African-American and Latino communities no longer see themselves as oppositional and that she has also been in touch with the A.C.L.U. and Planned Parenthood. “We’re starting to understand that we are going to walk in this together, and that’s really positive,” she told me.