I'm palestinian honduran so I wouldn't even bother trying to argue with the few people I'd run into that seriously consider race what makes someone western.

those "few people", aka the entirety of the population who actually cares about this shit lmao. Including the cunning ones who pretend to consider you guys "western" just for optics, and then support every standard right-wing American position

Nobody considers Christian, Portugese-speaking Angola to be "Western". Race is literally half the criteria.

I still don't see why it matters so much to american leftists tho

uhhh...because it matters to american rightists? If you spent a few months in America in a rural area with an Islamic name I think you'd learn pretty quick

"Western" = politically western European, and white

Russia isn't politically western so they don't fit
Poland used to not be western, but now is
Parts of the Balkans are part of the west (certainly not in the core though)
Japan and Korea are rich and vassal states of NATO, but are not white
America is technically mixed race, but the average white American is 98.5% white (and western european to boot), unlike any "white" person in any Latin country where even the least mixed people are still 20% Native admixed

Nothing in Latin America is Western in any sense other than cardinal directions. Yes, you're all Christian and part Spanish/Portu, but any "camaraderie" you see there is a completely one-way street--the people in Europe do NOT feel that way mutually about you, even if they don't get as violent about it as in the US. You could MAYBE make an exception for Argentina and Uruguay because it seems a lot of them (still not all) are close enough on racial criteria to "pass" visually. Places like Mexico and Colombia will never be western, because you can't be part of a group if your people get hatecrimed on sight (with no repercussions) in said countries .