Is banning a few students from wearing U.S. flag T-shirts really the best way to maintain order in a public school?

Really?

That’s what officials at Live Oak High School in Morgan Hill, Calif., insist they were doing last year on Cinco de Mayo.

And now a federal judge has concluded they were not outside First Amendment bounds.

But surely that ruling won’t stand.

And from afar, it seems that the best teachable moments in this controversy have long passed without the right lessons being taught.

Three families sued the Morgan Hill district, south of San Jose, after five students were told to turn their flag shirts inside out or go home when they wore them during the school’s observance of Cinco de Mayo, a Mexican holiday increasingly marked in the United States as a celebration of Mexican-American heritage and culture.

School officials said they were worried about the flag-wearing students’ safety because the previous year groups of Hispanic and Anglo students had yelled obscenities and threats at each other.

But if officials were so concerned about potential violence, why didn’t they take actions beforehand to defuse what probably were ongoing tensions in the school? They could have held an assembly focused on promoting mutual respect or encouraged teachers to include classroom discussions on honoring cultural differences.

A more thoughtful response could have benefitted wide swaths of the student body without singling out a handful of kids who wore flag-themed clothes — not drug slogans, vulgarity, racist symbolism or other displays carrying a clearer threat of disruption to the school’s educational mission.

The court record shows that one of the shirts had “America” written in cursive across a replica of the Declaration of Independence, for goodness’ sake.

Now, the Declaration did, at one point in U.S. history, amount to fighting words in a figurative sense. But telling a kid he can’t wear those words proudly in a public school seems to be a mindless distortion of government authority that stands the First Amendment on its head.

Nevertheless, U.S. District Judge James Ware in San Francisco dismissed the suit against the Morgan Hill district on Nov. 8. He said the principal and assistant principal “reasonably forecast” that the shirts “could cause a substantial disruption with school activities” and thus they acted within the limits set by the Supreme Court’s 1969 ruling in Tinker v. Des Moines Independent Community School District.

Tinker said students don’t shed their free-speech rights at the schoolhouse gate, but the court also allowed authorities to restrict those rights in the interest of maintaining order in the classroom.

That’s why federal courts have upheld such things as bans on Confederate flag displays in schools with a history of racial conflicts.

But letting a school official ban display of the United States’ national symbol on the spur of the moment because he’s worried about what might happen? That just seems to go beyond reasonable protection of student safety, especially when there’s no evidence that the students were deliberately standing in anyone’s face instigating violence.

Contrast Ware’s ruling with one by U.S. District Judge Laurie Smith Camp in Omaha, Neb., on the same day.

In that case, a mother and her three children sued the Millard school district over suspensions received for wearing T-shirts honoring a friend who was gunned down, allegedly by a street gang member. The students wore the shirts, which said “Julius, RIP,” for several days at two different schools before officials banned them. The student who designed the shirts said he was selling them to help raise money for his dead friend’s family; school officials said they could convey a gang message and provoke retaliation.

Camp ruled the suit could go to trial because officials hadn’t shown evidence that would justify “a well-founded expectation of disruption.”

I realize I can’t possibly understand what it’s like to be a public school administrator responsible for the education and safety of other people’s children. They need some leeway to exercise good judgment under often-trying circumstances.

But here’s the inescapable irony the Morgan Hill case creates:

Under Supreme Court precedent, an Occupy protester could burn a U.S. flag on the sidewalk as a political statement without getting punished. But in one corner of California, a high schooler can be sent home for wearing a U.S. flag T-shirt on campus if the principal’s worried it could start a fight.

Can somebody please alert the Colbert comedy team?

• Campbell is a columnist and editorial writer for the Fort Worth Star-Telegram.