What fact is most important in determining constitutionality in tinker vs des moines?

The most important fact in determining constitutionality in Tinker v. Des Moines was the students' right to free speech as protected by the First Amendment. The Supreme Court ruled that the students' silent protest—wearing black armbands to oppose the Vietnam War—did not disrupt the educational process and was, therefore, a form of expression that schools could not censor. This case established that students do not "shed their constitutional rights to freedom of speech or expression at the schoolhouse gate."