But this game was in Vegas.
So most of the chanters were probably legal and illegal Mexicans living in the US.
A few years ago there was a U.S./Mexico qualifier in Columbus, OH. The game was in February, 2009. I was there with my whole family. It was freezing cold. The Mexicans nearly outnumbered the Americans even back then. As I recall, we won that game 2 zip, or as they chant now, dos a cero. Maybe we won due to the temperatures that day.