Because we still have a culture that manages to trump all other cultures. It’s the Scots-Irish culture. See Jim Webb’s book “Born Fighting” or another book “Seeds of Albion”. Go to Houston but other than the lesbians its is still hillbilly central. Even the Muslimsend up becoming hillbilly and take on a rough independent demeanor.
Not saying it’s a universal truth. But it takes government funds and policies to make a ghetto that radicalizes. We still have vast areas of old America.
As of 2010, Anglos are barely above a quarter of the population of Houston and about a third of Harris County. I went for a short walk at a county park on the southwest side yesterday, and felt like I had no need to ever go to Mexico or Central America as it was all here. Alief, where I grew up and still work, is now called “The International District” and some of the street signs are partially in Vietnamese. I hear very few southern accents in the city proper anymore, except from some old timers. Of course, if you go to the outlying counties, you’re much more likely to hear them.