I am of the opinion that displaying a US flag should never be banned in the US whatever the context or motivation.
If the context is that it disrupts the learning environment in a school, then I have to disagree - the right of students to a safe, productive learning environment trumps the free speech rights of the offender, whether he uses the flag or not. Ask the Supreme Court if you don't believe me.
In fact, carving out exceptions to that rule in cases where offensive speech employs the flag (which is precisely what is being attempted here) is a recipe for disaster: it gives carte blanche to subversives to be as disruptive and offensive as they like, provided they wrap themselves in the flag (and so debase our national symbols, in the process).
And, again, the flag wasn't "banned" here. The flag continued to fly on the flagpole the entire time. And I would wager that the Pledge of Allegiance has been routinely recited in that school throughout this whole time. It was a specific instance of speech employing a flag display that was censured. Your dogged hyperbole on this point wins you no respect.
It is the symbol of our nation and should enjoy special status, especially at government funded institutions such as schools.
In the first place, the government that said flag represents does not fund the schools in question.
In the second place, special status for the flag is a two-way street. If we want to demand that the flag be flown freely and respected as a symbol of admirable national values - and
only those values - then we also have to insist that nobody appropriate it to convey other, contrary, offensive values. Anyone who does the latter is violating the special status of the flag by polluting its meaning, and so must be prevented from doing so. Else we have no grounds to turn around and insist that people interpret the flag as representing only admirable national values.
All of which is to say that preventing the students in question from misusing the flag for their own political speech is exactly the sort of thing you should support if you're serious about this proposition. Allowing the nefarious to abuse the meaning of the flag all they want, and then only invoking this special status when someone is offended by that speech, is just a perverse way of consigning the flag to right-wing reactionaries while pretending to respect it. It's dishonest, divisive, and offensive.
If they were indeed wearing US flag shirts to symbolize their support for the recently passed AZ law or to protest multiculturalism or illegal immigration, so what?
So such speech is contrary to the national values the flag represents, and as such debases a supposedly-sacred national symbol by reducing it into a token of reactionary nativism.
The flag can't be simultaneously a symbol of shared national values and a partisan token used for political attacks. You have to choose, and the refusal to do so - or the pretense that the rightwing values being espoused are synonymous with national values - is contemptible.
If they were wearing confederate flags to piss off black students, or swastikas to piss off Jews; I'd agree with the vice principle's actions. But the US flag does not symbolize hate as those other flags do and it should not be treated as if it did.
If we allow reactionaries to appropriate the flag for offensive speech, it will not be long before the flag represents nothing more than offensive positions. If that's not the fate you desire for the flag, then you have an obligation to resist its being so abused. You don't get to stand on the sidelines and blithely insist that the flag only means whatever you say it should mean while the craven appropriate it for other ends.
Or rather: you do, but all it achieves is a reduction in your intellectual and ethical credibility. You aren't going to impress anybody with insistence that the flag should only represent admirable, universal ideals coming out of one side of your mouth, when you're defending people who use the flag to convey contrary ideas out of the other. You're only going to provoke the question of whether you're malignly dishonest or astoundingly stupid.
To acknowledge that I do understand your point, I would suggest that next year the vice principle could nip this whole problem in the bud by asking all students to help commemorate cinco de mayo by wearing clothing with Mexican and/or American flags. This would serve the dual function of not allowing some small group to pervert the meaning of the US flag and reinforce its actual meaning to all the students. E pluribus unum.
Your grasp is too simple - minds with a bit of creativity will have no trouble finding ways to use the flag to offend, and the very attempt at pre-empting this will empower them and redefine the flag in ways contrary to the motivation there.
The only solution is to censor people who are determined to be offensive assholes, regardless of what flags they do or do not choose to employ in that effort. That leaves everyone else free to be cool to one another, and display whatever national symbols they may like without malice or fear. Or, I suppose, you could allow the schools to be reduced to trolling grounds for the reactionary children of teabaggers, in the name of "free speech." But that involves consigning symbols like the flag to becoming partisan tokens. If you want the flag to remain sacred (at least in school) and the schools to be functional, then you have to send home assholes who show up at school with flag-based political displays aimed at offending other students.