“Norteña is basically Mexican polka.”
Must be from the mass in-migration of Germans prior to WWI.
https://en.wikipedia.org/wiki/German_Mexicans
There was a reason the Zimmerman Telegraph mattered.
The Beeb did a series om changes in Mexico
http://www.bbc.co.uk/guides/zp2q7ty
Might be worth the time/bandwidth to read through the series.
Truth be told.
Mexico was Colonized by the Spanish hundreds of years ago.
There are Spanish Mexicans and there are Native Mexicans.
The Spanish Mexicans have complete disdain for the Natives and are happy to see them “migrate” to the US.
The Native Mexicans are easily identified by how they look and their smaller stature.
The ruling class in Mexico is run by Spaniards.