As nearly 170 new medical students filed into a University of Michigan auditorium on Sunday, some wondered how they would explain to their overjoyed parents that they were going to walk out of the ritual marking the start of their studies.

Each member of the incoming class had their own calculus about whether to stay seated during the keynote address by Kristin Collier, an openly antiabortion health provider, or join fellow students in a peaceful protest. When the day came, about 70 people quietly rose from their seats and walked out as Collier took the stage — a show of dissent one month after Roe v. Wade was overturned. A clip of the walkout quickly went viral, with one video viewed more than 15 million times by Tuesday morning.

For some conservatives, the walkout was the latest example of “cancel culture” on university campuses. For others, it was a welcome sign of young people standing up for a procedure now severely restricted in some states.

But for the students involved, it was a chance to advocate for one of the four pillars of medical ethics: autonomy.

“We saw an opportunity to utilize our positions as future physicians to advocate for and stand in solidarity with individuals whose rights to bodily autonomy and medical care are endangered,” the organizers said in a statement to The Washington Post.

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A University of Michigan spokesperson said in a statement that Collier, the director of the medical school’s health, spirituality and religion program, had been selected to give the keynote address “based on nominations and voting by ... medical students, house officers and faculty.”

Collier, who has taught at the University of Michigan for 17 years, did not respond to a request for comment from The Post. The university spokesperson said Collier is not speaking to the media.

In a June interview with the Catholic newsletter the Pillar, Collier detailed her “conversion to a pro-life person” after years of being secular and staunchly “pro-choice.” A month earlier, she posted on Twitter that she “can’t not lament the violence directed at my prenatal sisters in the act of abortion, done in the name of autonomy.”

In her Sunday address, Collier urged students to “get to know your patients as human beings, not just as their scans, labs, chemistry and data.” Although she didn’t explicitly mention abortion, she appeared to address the controversy by saying, “I want to acknowledge the deep wounds our community has suffered over the past several weeks.”

“We have a great deal of work to do for healing to occur,” she continued. “And I hope that for today, for this time, we can focus on what matters most — coming together to support our newly accepted students and their families with the goal of welcoming them into one of the greatest vocations that exists on this earth.”

One student told The Post that after the Dobbs decision, having a speaker who has expressed antiabortion views “felt inappropriate and like a slap in the face.”

“She can hold whatever opinion ... but I think the professional sphere is where one needs to be objective, especially as health-care providers,” added the student, who spoke on the condition of anonymity because of safety concerns over backlash to the walkout.

Before the ceremony, the students created a poll to gauge whether to take action. When about 91 percent of respondents said they were either against or strongly against having Collier speak, according to the organizers, they created a petition to have her removed as the keynote speaker. They also proposed having a conversation with Collier at a later date — just not during a ceremony considered a rite of passage in their field of study.

University officials, however, stood by their decision. Collier “never planned to address a divisive topic” during the ceremony, the statement read.

“The University of Michigan does not revoke an invitation to a speaker based on their personal beliefs,” it added.

As students prepared for the white-coat ritual, some were planning their protest. They wore pins with abortion rights slogans to the ceremony, recited an added line about patients’ rights to their statement of ideals and then eventually walked out.

“You could tell there was this overwhelming sense of pride in the air. They didn’t know each other before, but there was this sort of big breath of relief when everyone got outside and they were able to stand together in solidarity,” said Brendan Scorpio, a Detroit-based social organizer who attended the ceremony and posted the clip of the walkout. “It was a very meaningful, powerful moment.”

A large group of students just walked out of Notre Dame's commencement during VP Mike Pence's address. #ND2017 pic.twitter.com/g3dCuqPbXg

The debate surrounding Collier’s speech is preceded by decades of culture clashes on university campuses, said Peter Cajka, who teaches in the department of American studies at the University of Notre Dame. The University of Michigan was known for the student activism it sparked in the 1960s.

“These culture-war-type debates at universities erupted in the ’60s as the university became a more political space,” Cajka said.

More recently, students at Boston University left an April lecture featuring a conservative political commentator, the school’s newspaper reported. In 2017, graduating seniors at Notre Dame walked out of their commencement ceremony as Vice President Mike Pence delivered an address.

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But Cajka sees a switch in the clashes occurring on campuses today. Politics are bleeding into areas that were historically apolitical, such as medicine, technology and science, he said. The catalyst of these protests often boils down to speakers seemingly embodying “the politics people are pushing against at times when said politics are at an issue.”

“Without the Dobbs decision, does this speech even matter? No,” he said of Collier’s keynote. “Because this person who’s pro-life, well, that’s normally just an opinion. But now it seems like it has or represents some political power.”

Michigan is among the handful of Midwestern states that still protect access to abortion, though the procedure is subject to restrictions.

Its flagship university and medical center “remain committed to providing high quality, safe reproductive care for patients,” the University of Michigan said.