“It’s not that Orange County’s values have changed; it’s that the Republican party’s values have changed. And they’ve completely lost touch with reality and the vast majority of voters,” Rouda told me as he sipped a Starbucks iced latte with soy milk just 15 miles from Richard Nixon’s “Western White House.”

While the demographic trends show no hint of weakening, it’s an open question whether those disaffected Republicans are, like Rouda, permanently done with the GOP—or whether they can be coaxed back in a post-Trump world. There is a fierce battle already underway, from the marble halls of the Capitol to the beaches of southern California, to decide Orange County’s fate—and, in turn, that of the House majority post-2020…

Politicians in Orange County, like in many American suburbs, are becoming less dependent on these older white voters for their coalition. Orange County, in a very short time, has become younger and less white—and when paired with Trump’s election in 2016, that shift cemented Orange County’s status as ground zero for Republicans’ struggle to attract young voters, moderates and minorities, especially in suburban America.

“Since Donald Trump came into the picture, we have seen this huge uprising,” Ada Briceño, who chairs the Orange County Democratic Party, told me.