The parent believes there's parallels between the demography-driven expansion of radical Islamism in certain countries (I'm guessing in Europe, although he didn't specify) and and the demography-driven expansion of Mexican nationalism in the American Southwest.
I meant to remove it, it's a distraction. There are Mexican political groups who advocate for a similar policy to regain control of many western states, who they believe were unjustly ceded from Mexico.
These folks are very much in the fringe, and I shouldn't have mentioned it,