Let them speak! Intellectual diversity means don't cut off the mic, even if you disagree.

You may have heard about the impromptu graduation speech that valedictorian Paxton Smith gave last month at her Dallas high school. Abandoning her pre-approved remarks on the influence of mass media, Smith delivered a scathing attack on the recently passed Texas "heartbeat" law to restrict abortion.

The speech went viral and the internet exploded with praise from prominent liberals, including Hillary Clinton (who hailed Smith’s “guts”) and comedian Sarah Silverman (who called her "brave.") “Paxton, thank you for having the courage of your convictions,” tweeted former Texas Rep. Beto O’Rourke. “May we all use our place in this democracy to fight for what we believe to be right and follow your example!”

'Freedom for speech that I like'

But if Smith had gone off-script to commend the new measure, which prohibits abortion when a fetal heartbeat is detected, would people like Clinton and O’Rourke be applauding her courage and outspokenness? I think not. And that speaks to a much bigger problem in our culture, which is on not-so-grand display every graduation season.

Call it "freedom for speech that I like." When a young person takes a stand for something we agree with, we stand up and cheer. But if it’s not to our political taste, we condemn it as too political. And you can't really have free speech on those grounds.

So when a student speaker at New York University’s 2019 graduation praised the boycott, divestment and sanctions movement against Israel, President Andrew Hamilton denounced him for using the commencement ceremony to “express his personal viewpoints on BDS.” The president also said graduation should be a “shared, inclusive event.”

And earlier this month, at a high school in New Jersey, officials cut off valedictorian Bryce Dershem’s microphone when he started discussing his experiences as an LGBTQ student. Before approving his prepared address, officials had urged Dershem to remove all references to sexuality and mental health issues on the grounds that such topics were not “inclusive.” Never mind that Dershem was making a plea for the inclusion of sexual minorities in his school. Grabbing Dershem's speech from the podium, his principal crumpled it into a ball – check out the Youtube video, if you don’t believe me – and told Dershem to read his pre-approved address.

Offsite speech: Why Supreme Court case about cheerleader's Snapchat rant matters to students everywhere

Are we seeing a pattern here? Meaningful speech is almost never “inclusive,” if that means agreeing with everyone else. And if it does, it’s probably not very meaningful. That’s why so many graduation addresses are littered with clichés, which don’t teach us much of anything.

And too many schools want to keep it that way. A California high school cut off a valedictorian’s microphone in 2018 when she condemned how it had handled sexual assault complaints. In Pennsylvania, a school pulled the plug on a 2017 graduation speaker when he criticized the school officials for – you can't make this up – ignoring student voices and ideas.

Watch that video, too. The mic went quiet but the student continued to talk, until a principal ushered him off the stage. His classmates gave him a standing ovation. And above the din, you can hear someone shouting, “Let him speak!”

Censoring the controversial

That's also what the Supreme Court said last week, when it ruled that another Pennsylvania teenager couldn't be suspended from her cheerleading team for a profanity-laden Snapchat post denouncing the team and her school. Context matters, of course. If she had used the same off-color words in class – or in a graduation speech – the school would have been within its rights to cut her off.

But Bryce Dershem and other commencement speakers haven't been censored for being vulgar. Instead, their real sin was being controversial. They were saying something significant, about issues that matter to them, and their schools didn't want that.

Eboo Patel on Ramadan at Starbucks: How companies can profit by respecting religious diversity

To its credit, Paxton Smith's high school let her finish her address without silencing her microphone. But the school board president, Karen Clardy, said Smith’s actions were “unexpected and not supported” by her school district, which would try to “prevent something like this from happening again.”

That’s why the rest of us need to make sure that it does, by raising our own voices on behalf of students' free speech. And it shouldn’t matter if we agree with the speech or not. I share Paxton Smith’s opinion on abortion rights, so it’s easy for me to praise her for speaking out about them. It’s much harder to allow someone to have their say when you think they're wrong.

Let the students speak! "Freedom for speech that I like" frees up American schools to censor anything they don't like. That's not freedom at all. You might even call it un-American.

Jonathan Zimmerman teaches education and history at the University of Pennsylvania. His latest book, co-authored with Signe Wilkinson, is “Free Speech And Why You Should Give a Damn.”

You can read diverse opinions from our Board of Contributors and other writers on the Opinion front page, on Twitter @usatodayopinion and in our daily Opinion newsletter. To respond to a column, submit a comment to letters@usatoday.com.

This article originally appeared on USA TODAY: Valedictorian speech: Don't cut off microphone, even if you disagree.