it is not a US holiday, it is celebrated here is all, not out of some respect for the Mexicans winning a battle against the French, it is just an excuse to party. Read the link you posted, here is more for you
http://en.wikipedia.org/wiki/Public_..._United_States
It dont matter why they wore what they wore, the school admin should have explained that to the kids that complained in the first place. The same right that allows them to celebrate a holiday that has nothing to do with this country, is the right that allows the others to wear what they wore. The school administrator should have taken the opportunity to explain to kids what this is all about and instead took the approach of someone with little education, at least when it comes to educating children.
This whole thing should never have happened, but things being what they are it did happen, but put the blame where it belongs, with an inept school administrators that used either their own prejudice against the country that gives them a job, educated them and protects them to make his decision or they are just that fucking stupid and should not be in the position of educating kids.
What a brain, let me show these kids they are being assholes wearing their own countries colors on a Mexican holiday, thats just trying to cause trouble because the Mexican... decedents (of course all here legally) could be offended, so we will just take their rights away. We have the power, we are the school! Say the kids planned it, still changes nothing at all, the reaction was ignorant.
But hey, it is cool to bash the USA... all together now