The LA Times usually puts out a Dems vs. Repubs interactive map during Presidential elections, showing each precinct. I usually have to go to other sources to see how ALL political parties fared. This year I voted for Gloria La Riva, who was representing the Peace and Freedom Party in California.
Here's LA, Orange and San Diego Counties. As you can see, the northern half of LA County (mainly the Antelope Valley) is reddish, while the rest is blueish. There are pockets of Trump supporters in wealthy LA County areas, like La Habra Heights and the Palos Verdes Peninsula (Rolling Hills). Most notably, parts of Beverly Hills also have Trump supporters; Beverly Hills is usually considered a Democrat Party area.
https://www.latimes.com/projects/tru...ts-california/