Unfortunately, I must disagree on this. As much as I dislike FOX news and that coterie of wingnuts, there is a more basic issue here. If the Mexicans at this school are so offended by the American flag (on any day), why are they here to begin with? As much as their underlying motivations may have been nationalistic, xenophobic or anti-immigrant, those kids have a right to wear the flag of their country (in so far as it does not conflict with school dress codes) on any given day of the week. If there is a fundamental clash between the cultural meaning of the American flag and the 5th of May, the flag of the country that you are in trumps those considerations.