Christiansburg, Va., High School students gather after being suspended from school property for wearing clothing displaying the Confederate flag. (Matt Gentry /Associated Press)

ADMINISTRATORS AT Virginia’s Christiansburg High School suspended 23 of their students last week for refusing to remove shirts, belt buckles and jewelry bearing the Confederate battle flag. It should worry every American when any arm of the state punishes students or anyone else for what they wear, what they say or how they say it. In this case, however, the administrators have a point.

When to restrict student speech has been a thorny issue for decades. Overzealous school administrators have too often infantilized their students by denying them their rights to peacefully express themselves, on the grounds that they might offend, disrupt class or simply express views that officials don’t like. Broad restrictions on student speech not only silence those who have every right to express themselves, they offer a pernicious civics lesson, disserving students who should learn to engage in this country’s roiling, raucous public debate.

Spurred by high school students who were punished for wearing arm bands to protest the Vietnam War, the Supreme Court set restrictions on the would-be censors in 1968. In Tinker v. Des Moines Independent Community School District , the court ruled that schools can restrict student expression, but only if it will “materially and substantially interfere with the requirements of appropriate discipline in the operation of the school.” Moreover, a school “must be able to show that its action was caused by something more than a mere desire to avoid the discomfort and unpleasantness that always accompany an unpopular viewpoint.”

This standard would restrict far too much speech outside of the school environment. But within school, it balances the obvious necessity to maintain order with the basic rights of students and, indeed, the centrality of free speech to the health and dignity of the country’s democracy..

In the Christiansburg case, school officials did not have to rely on an unwarranted or dangerous deviation from constitutional principles to justify punishing their students. School officials argue that the dress-code prohibition on displaying the Confederate battle flag stems from racially motivated fighting on campus in the early 2000s, some of which was related to displays of the flag. Not only did school officials have “more than a mere desire to avoid the discomfort and unpleasantness,” they claim to have concrete experience that not doing so risks violence.

That logic does not, however, justify the school district’s much broader dress-code policy, which bans items “that reflect adversely on persons due to race, gender, creed, national origin, physical, emotional, or intellectual abilities; or that are considered to be distracting or inappropriate attire.” Read broadly, this could rule out everything from a shirt with the n-word on it to a hoodie bearing the Washington football team’s logo to a button depicting a “Far Side” cartoon. In Christiansburg, as everywhere else, school officials must draw a more careful line, recognizing that the goal is not to protect students from all offensive speech, but only to prevent offensive speech from making schools chaotic or unsafe.