San Diego , California -LRB- CNN -RRB- -- When is wearing a T-shirt with the American flag on it considered provocative ? Answer : When you wear it to a high school with a dress code that explicitly prohibits `` any clothing or decoration which detracts from the learning environment . '' And when the high school , where 20 % of the 1,300 students are English-language learners and 18 % come from low-income families , has been described by the San Francisco Chronicle as having `` an ethnically charged atmosphere . '' And when , despite concerns about potential violence , you and some of your friends make your patriotic wardrobe choices on , of all days , Cinco de Mayo . Last week , Chief U.S. District Court Judge James Ware said as much when he dismissed a lawsuit by a group of students and their parents against the Morgan Hill Unified School District in North California . The plaintiffs had alleged that , on May 5 , 2010 , the students ' rights to freedom of speech were violated when Live Oak High School Assistant Principal Miguel Rodriguez ordered them to remove or turn inside out T-shirts bearing the American flag . The students refused , and two of them were sent home . Under ordinary circumstances , wearing a T-shirt with the American flag on it would probably not be a big deal . But this high school is no ordinary place , especially not on Cinco de Mayo . It 's a cultural powder keg . The previous year , in 2009 , a group of Mexican students marked the holiday by walking around campus holding a Mexican flag . A group of white students responded by hanging a makeshift American flag from a tree and chanting `` USA . '' According to the Chronicle , tensions flared and the two groups faced off with profanity and threats . Little wonder that when some students showed up at school wearing T-shirts with American flags on them administrators decided to err on the side of caution . Meanwhile , the judge did the right thing in dismissing the case and declaring that administrators had the right to take preventive action if there was a `` reasonable fear '' of violence . Score one for common sense . Can you imagine where we 'd be if the court had gone the other way and stripped school officials of the power to maintain order ? It 's easy for conservative radio talk show hosts and other right-wing commentators to criticize the administrators , but they were n't there . They 're speaking from ignorance . They do n't have even the most basic understanding of the mood at the high school or the events of previous years . Conservatives are confused . For the last four decades , they have chipped away at the idea that students ' free speech rights should trump every other consideration . The Supreme Court established those rights in 1969 in a case called Tinker v Des Moines Independent Community School District . In that case , a group of high school and junior high school students were suspended when they wore black armbands to protest the Vietnam War . The high court declared that students do n't `` shed their constitutional rights to free speech or expression at the schoolhouse gate . '' But since Tinker , and at the urging of conservatives , the Supreme Court has curtailed First Amendment rights of students , especially when the expression of those rights is disruptive , obscene or might lead to violence . It did so in three other cases : Bethel School District v Fraser -LRB- 1986 -RRB- , in which the high court held that a high school student 's speech during an assembly -- filled with sexual innuendo -- was not protected ; Hazelwood v Kuhlmeier -LRB- 1988 -RRB- , in which the justices held that schools can regulate the content of student newspapers ; and Morse v Frederick -LRB- 2007 -RRB- , in which the Court held that school officials can restrict student speech at a school-supervised event even if it takes place off-campus . That 's the new legal reality , and it 's one that conservatives helped create . Now they have to live with it . The other problem is the parents , who did their offspring no favors by encouraging them to play the victim and call a lawyer . They were so eager to sue and teach their kids to stand up for their rights that they neglected to teach them that , in our system , rights come with responsibilities . Like this one : Americans have the responsibility to treat one another , and one another 's cultures , with respect . Just because someone shows cultural pride -- St. Patrick 's Day , anyone ? -- does n't mean it 's an expression of anti-Americanism . Quite the opposite . America is all about coming together as one , while preserving the cultural attributes that make us unique . There 's the rub : The students who brought the lawsuit against school officials claim to be proud of the American flag . But it 's obvious they do n't have the foggiest idea what it represents . And , when they had the chance , their parents failed to teach them . Follow CNN Opinion on Twitter for more views on the news The opinions expressed in this commentary are solely those of Ruben Navarrette Jr. .