No law was broken. The only legal issue isn't about whether or not the people or their kids were in the wrong, it's whether the school had the right to ban the shirts, which they typically do, but usually this is cited under a 'no messages' rule. i.e. as far as the law is concerned wearing a John Edwards for Pres t-shirt, a islam is bad t-shirt, and a save the whales t-shirt are exactly the same, you ban all or you ban none. Your suggestion would be akin to making someone who wore a t-shirt saying 'We only have one planet' wear a t-shirts saying 'Torch the rain forests'.

Let's keep in mind that the first amendment is there to protect unpopular speech, popular speech has never needed protection, no one ever gets dragged away by secret police in the middle of the night for saying how much they like their dictator.

I think these parents are ignorant bigots, but my opinion, and yours, mean nadda. The t-shirts are totally legal, but schools can ban things as disruptive and for pretty much the same reason they can ban students from having cellphones. When they do they leave themselves open to legal action if they can be shown to have ignored equivalent offenses after being alerted to them. The shirt is simply no different than one saying 'Jesus saves' or 'Allah ackbar", neither of which I find offensive, since I consider them true statements, but morally and legally no different than ones which say 'Jesus doesn't save' or "God isn't great" Now, I wouldn't consider a parent bigoted, wicked or ignorant for letting their kid wear a shirt which said 'Jesus saves' to school, so where's the difference? The school has a right to ban things as distracting or disruptive, to do so they need only show reasonable evidence that something is either and enforce it with some degree of even-handedness.