"We would hope that honoring someone at commencement would mean that we were upholding someone who adheres to our Catholic values as much as possible," she said.
The Rev. Richard McBrien, a Notre Dame theology professor, called the honorary degree a "red herring."
"If he were not getting an honorary degree, but were speaking at the commencement, there would still be the same protest," he said. "It's a custom of Notre Dame to give an honorary degree to all commencement speakers, whether they're president of the United States or anybody else."
It is not just students who are boycotting the ceremony. Bishop John D'Arcy of the Diocese of Fort Wayne-South Bend, Ind., where Notre Dame is located, said in March that he will not attend Sunday's commencement because of Obama's "long-stated unwillingness to hold human life as sacred."
"While claiming to separate politics from science, he has in fact separated science from ethics and has brought the American government, for the first time in history, into supporting direct destruction of innocent human life," D'Arcy said in a statement. "My decision is not an attack on anyone, but is in defense of the truth about human life."
This will be the first Notre Dame commencement D'Arcy will miss in his 25 years as head of the diocese.
Some students are choosing to attend the ceremony, but stage a silent protest.
"We are planning on putting a symbol on top of our mortarboards with a cross and a pair of baby feet, just as a silent witness of our disagreement with the university's decision to bring Barack Obama as the commencement speaker and to give him an honorary degree," said Stephen Govea. "As the president of the United States, he is an exciting person to have in any capacity. Unfortunately, as I said, he is just tragically opposed to us on some very fundamental issues."
Earlier this week, the White House aggressively pushed back against the notion that the opposition of one group at Notre Dame is representative of widespread feelings on campus or among Catholics in general.
"I think there's one group organizing a boycott," Gibbs said. "And, as best I can understand it, there are 23 groups that have formed in support of the president's invitation."
On Saturday, ND Response, the group leading the anti-Obama demonstrations, planned to hold a candlelight vigil and Sunday planned to stage a meditation ceremony and a rally to pray for graduates.
ND Response is a coalition of 11 anti-abortion groups, including the Notre Dame Right to Life organization and the Notre Dame College Republicans.
Part of all three events, according to an organizer, is a protest of the university honoring "a political figure who supports abortion and stem cell research."
The group said it is not a Democratic or Republican issue, but about Catholic doctrine: "Our objection is not a matter of political partisanship, but of President Obama's hostility to the Catholic Church's teachings on the sanctity of human life at its earliest stages."
But many students said ND Response's very vocal and public demonstration is not indicative of the overall enthusiasm and excitement of having the president speak at their commencement.
E. Brennan Bollman, who will deliver Sunday's valedictory address, said that the "sensationalism" over the president's speech is coming from outside the campus.