VAHEGURU JI KA KHALSA, VAHEGURU JI KI FATEH
I do believe that the Zafarnamaa has stated that when ALL OTHER means have failed, THEN is is righteous to pick up the sword (aka. resort to violence). Given the details, have all the other means been exhausted?
Look, getting into a fight may work for you as an individual, but understand a few things: A) It will get you suspended and will be a blot on your academic record (I should know, I was blocked from getting on the National Honors Society thanks to a suspension on my record);
It does nothing to address the problem at the school level or for future Sikhs attending the school; C) Until a protocol is developed to take care of these problems at an administrative level, there is no guarantee that the problem will not be repeated on the same person over and over, but the same or other students (you all are under the impression that if someone gets beat up, they will stop the taunting/bullying - I beg to differ and have seen cases to the contrary - enemies have friends, friends who then team beat-down the enemy).
Principal does not care? Make him/her care but "reminding" of his/her duty to protect the students with legal consequences if it is not taken care of. Using the discrimination card is very important (after all, that is what is happening), as is the word lawyer and court case - gets people energized quite readily to help your cause. This way, they will also end up perhaps developing a procedure on how to handle any such future cases. If the principal is still not receptive, go up the chain and contact the superintendent of the district and make sure to let him/her know of the principal's lax attitude. Changes will occur quite rapidly after that. Every other community follows this procedure (proactive African American community in the U.S. will report these cases in a minute and secure rights for themselves. We should learn from them).
Contacting the organizations mentioned above is vital, as not only do they handle the cases and remind the school district of its responsibilities (becomes quite effective when the Sikh representative at the end of the table is either a lawyer or can summon on easily), but also provide an avenue to provide educational seminars at the school for the teachers and the students. Bhai Jasjit Singh himself was (still is?) involved in visiting schools with other members/organizations of the Sikh community and participated in presentations on Sikhism and tying Dastaars on Sikh schoolchildren and answering the questions of the schoolchildren and the teachers. Such efforts go a LONG way as preventative measures and provide a contact point in the community in case the school needs assistance in any future cases or needs a refresher presentation on Sikhism for new teachers/students.
We need to stop thinking of every event as isolated and and opportunity to "Chatkaa the enemy" and start to understand that this is a huge problem, with every case being an opportunity to educate, empower and prevent this from ever happening in an entire school district. Otherwise, we will continue to have fights and bullying and add suspensions to our childrens' school records if we do not take the additional steps to handle this on a proactive, rather than a reactive, manner.
And yes, I attended the American school system from 2nd grade onwards, so I am not speaking theory - been there, done that, seen it, been a victim to it and survived it.