Some graduating seniors at the University of Notre Dame say they are planning to protest the presence of Vice President Pence at their commencement by standing up and quietly walking out of the ceremony. School officials say they won’t try to stop them.

Pence will give the commencement address at the nation’s most prominent Catholic university on May 21 at the campus in South Bend, Ind. In the past, the university invited newly inaugurated presidents to give the address in their first year of office — and six previous presidents accepted — but this year was different.

Thousands of students and faculty members signed a petition asking Notre Dame’s president, the Rev. John Jenkins, not to invite him, saying that they did not think Trump’s actions and behavior were in line with the school’s values. While there were Trump supporters who wanted him to speak, the school decided to instead invite Pence, a former Indiana governor.

A coalition of student activist groups at Notre Dame called We StaND For is planning the walkout to protest policies Pence pursued as governor that they say targeted the most vulnerable. Other groups from outside the school community will, at the same time, hold a protest just south of campus to show solidarity with the students, according to Bryan Ricketts of We StaND For. One of the participating groups, South Bend Equality, wrote in a statement about why it is participating:

Our members lived in South Bend when Mike Pence was governor. We know all too well how his policies endangered or caused direct harm to public education, health care, women’s rights, the environment, LGBTQ individuals, immigrants and refugees, reproductive rights, local infrastructure, the economy of our state, and more.

Other groups participating in the off-campus protest are We Stand For; We Go High! of St. Joe County, Ind.; Michiana Alliance for Democracy; Alliance for Democracy; the Nu Black Power Movement; Inclusive Michiana; Planned Parenthood of Indiana & Kentucky; and the IWW Local 26.

Paul Browne, vice president for public affairs and communications at the University of Notre Dame, said that student protest leaders have already talked to security police and other officials on campus about their plans, and the school isn’t trying to stop them. He said the protesters plan to silently leave commencement “at some point and do it in a respectful manner.”

The action, he said, does not surprise school officials because the university has repeatedly been the scene of protests.

For example, some antiabortion activists protested President Barack Obama when he spoke at the 2009 graduation ceremony, and there were protests too for Vice President Joe Biden at the 2016 commencement, he said. Biden was there to receive the Laetare Medal, along with former Republican house speaker John Boehner; the award is the highest given to Catholics in the United States and recognizes service to the Catholic Church and society. There were protesters on campus, too, for a recent talk by conservative political scientist Charles Murray.

“It’s not unusual for us,” he said.

Pence protest organizers are using the hashtag #WalkOutND to build support for their effort and say they expect scores of students and many more family and friends in the audience to participate. There will be about 2,000 graduating seniors at the ceremony.

Browne said the school was not concerned about the protests. “Virtually our entire discussion at the moment is about the weather,” he said. Thunderstorms may drive the ceremony from an outside venue, where students can have unlimited tickets for guests, to an inside auditorium where tickets will be limited, he said.

(Correction: An earlier version said the six previous presidents had spoken at Notre Dame; it was six former presidents. Also clarifying wording on past protesters.)