the American flag was little different than a slogan saying "deport anchor babies."
So are you suggesting that t-shirts bearing that slogan should be censored by the government? I find that offensive.
I find those t-shirts, in the same context, would be similar to yelling fire in a crowded theater, swatting someone, or committing slander. All three of these similar instances could be defended by citing freedom of expression or free speech. All three are expressions I would like our laws to limit. The wearing of t-shirts is far less extreme than any of these three examples, but the reasoning on why freedom of expression should be limited in all four cases is the same.
Teenagers should enjoy the same free-speech protections that the rest of us enjoy, even if it offends some people.
While adults are not prevented from using hate speech (or any other symbols that promote hate), there are places where they are not allowed. You will probably be asked to leave a courthouse if you start spouting hate speech during a trial, or even when standing in line at the DMV. I am also okay with this, even though both are government buildings.
Then they could just forbid all clothing with slogans or flags of any kind.
I see no reason to go to this extreme. Schools generally use the guideline of preventing a hostile learning environment when determining what to allow on campus. I believe having a cohesive learning environment is more important than students giving up a few liberties while at school. I also believe children's property rights should be respected, but would give teachers the ability to confiscate calculators during math tests if necessary.
Finally, I have to disagree that a US flag is somehow like making a political statement about immigration. It's the flag of this nation; if wearing it is offensive to someone, regardless of the day, that seems rather ridiculous.
You are more than likely bright enough to realize the students were making a political statement with those t-shirts. They even freely admit it. And this case in particular has nothing to do with the action being offensive. Being offensive is okay. Creating a hostile learning environment is the heart of the matter, not offensive speech.