Greasy pork sandwich; dirty ashtray

I'm loving having Bill Paxton on my picture-radio-box every Sunday night in the pleasing HBO soap "Big Love." I've been a huge fan of Paxton's since John Hughes's 1985 classic "Weird Science" and his wonderfully unhinged Chet; he followed that up with 1986's unforgettable "Aliens" as the delightfully.... unhinged... Pvt. Hudson.

Anyway, I was just wondering why in "Weird Science" if the Donnelly family were from suburban Chicago, why was their eldest son somehow Texan?