I heard somewhere today that Spanish radio was passing the messages about the flags because the mexican flags were causing a backlash.
It is clear that when there is an English speaker up at the mic, the crowd doesn't react or understand until the Spanish translator follows up. Then they scream.
Just caught some coverage of the demonstration in Phoenix. Looked like a shot from a helicopter, and all I could see were US flags being carried.
Interestingly, EVERY one of the hundreds (thousands?)I could see in the picture as the camera panned the crowd were wearing identical-looking white shirts. Couldn't see what was written on them, but not one shirt of a different color was obvious.
Yes this has been a thorn