Schools could also argue that it's tOo DiStRaCtInG to refuse to do the pledge as well. That's a common loophole I had to deal with in middle and high school.
Everything has at least one loophole in it.
Discussion
As a student, I was frequently sent to the principal's office—almost daily—for exercising my constitutional right. I would remain seated, put my left hand over my heart or face out the window instead of at the flag in silent protest, until they finally just gave up and allowed me to remain seated. I am patriotic in my own way; I will not be forced me into blindly pledging allegiance to anything I do not fully support.