Did you know that more than 65% of Mexicans are descendents of Spain? What you have is the descendents of one European nation getting angry with the descendents of other European nations for being here.
These folks are posers, nothing more, nothing less.
You are absolutely right. Spain came in and claimed massive land from the indigenous population. When Spain pulled out, it granted the land it stole to Mexico. Spain left in about 1825. Mexico lost the land to us in the Mexican/American war around 1850. And then we compensated Mexico to boot.
These Mexican blow-hards don’t know their history at all.
Not hard to figure this wasn’t covered in their 0 to 8th grade education. That’s what illegals have 0 to 8 years. Much of them only have about four years of formal education, but they think they should be in charge up here.
It isn’t really history they are believing in. It’s chutzpah. Say something illogical with enough conviction and voila, it gets to be treated as a Truth.
This is how God chastens a people for believing doctrines of demons.