I’ll add one data point. 20 years ago, during college, I had a friend who had attended Bonita Vista High School in Chula Vista. One day, while hanging out, I met one of his former high school friends. Sure enough, that friend did indeed live in Tijuana (with his entire family) but had crossed the border every day to attend high school in the US. He openly admitted this.
I couldn’t understand how this was “legal”, considering that he wasn’t a U.S. resident. Obviously, it wasn’t legal. Basically, it was the phenomenon that BG has been talking about. I was kind of shocked by it all.