Once reserved for cheesy senior photos at campus landmarks, college commencement exercises have graduated into something different six months after Donald Trump was elected president: a battleground for protesting conservative policies and the people who promote them.

The latest quarrel ended Friday, when historically black Texas Southern University canceled one of its scheduled commencement speakers – John Cornyn, the Republican senator from Texas who is on Trump’s short list to head the FBI.

The rescinded invitation came after students threatened to boycott a commencement ceremony featuring Cornyn and signed a petition on change.org demanding that the university drop the senator because of his policy stances.

The petition called Cornyn’s presence an “insult” to Texas Southern and suggested that students have a right to boycott their own graduation ceremony if the administration kept Cornyn as speaker against their wishes.

The university’s capitulation has drawn Texas Southern into the debate about free speech at U.S. colleges and universities that has stirred controversy several times when conservative speakers have planned to set foot on campus.

The protests often make national headlines and are something officials have to take seriously.

Education Secretary Betsy DeVos was booed as she spoke earlier in the week at the commencement ceremony of Bethune-Cookman, another historically black school. Administrators there did not act on petitions asking that DeVos not be allowed to speak.

Instead, DeVos had to raise her voice as she thanked mothers who attended the ceremony. Moments later, about 380 students turned their backs on her.

Earlier this year, Berkeley administrators flip-flopped on a decision to let Ann Coulter speak on campus over safety concerns surrounding student protests. Coulter declined their second offer and roasted California university officials in the media and on Twitter.

At Texas Southern, more than 800 people had signed the petition asking administrators to drop Cornyn as a commencement speaker. By Saturday morning, organizers had declared victory with a little red flag at the top.

“The decision to host Mr. Cornyn as a keynote speaker sends the message that the policies and views he has advocated and supported, including both discriminatory policies and politicians, are acceptable by the university and subsequently the student body,” says the petition written by Rebecca Trevino.

It ticks off a list of Cornyn’s policy stances:

He voted for DeVos for U.S. Education secretary and against expanding a children’s health insurance program.

And he voted in favor of requiring a voter ID in federal elections, a move critics say makes it harder for blacks and other minorities to vote.

In a statement on Facebook, the university said it was trying to keep commencement positive, with a focus on students and their families.

“Every consideration is made to ensure that our students’ graduation day is a celebratory occasion and one they will remember positively for years to come,” the statement said. “We asked Senator Cornyn to instead visit with our students again at a future date to keep the focus on graduates and their families. We, along with Senator Cornyn, agree that the primary focus of commencement should be a celebration of academic achievement.” The school wasn’t immediately available for comment.

Trump’s administration worried some leaders this month when he released a statement that some interpreted to mean that a key funding source for historically black colleges and universities might not be constitutional.

A few days later, Trump said in a statement that his previous comment “does not affect my unwavering support for HBCUs and their critical education missions.”

Cornyn is the second-ranking Senate Republican and has been more vocal in his support of Trump in recent weeks. He was one of four people scheduled to interview Saturday to serve as the FBI’s new director, after James Comey was abruptly fired Tuesday.

In an email to The Washington Post on Saturday, a spokesman said “Senator Cornyn was honored to be invited to address TSU’s graduates, but he respects the administration’s decision and looks forward to continuing to engage with the university in the future.”