The dots are counties - the largest red one above LA is Kern county - Tulare county is the smaller red dot above it to the right
This is a clearer version of that map. The other two much smaller red dots above LA are Kings and Inyo counties - this map is based on 2016 presidential results, as Inyo went blue in 2020 (by only 14 votes though)
Expat is short for expatriate, not ex-patriot. Both expatriate and patriot do come from the same Latin root (patria, fatherland) via French.
But yes, expatriate means someone who lives outside (ex) of their fatherland (patria) - can be used for both immigrant or emigrant, depending on context.