SOUTH BEND, Ind. — Jimmy Carter came to Notre Dame in 1977. So did Ronald Reagan in 1981 and George W. Bush in 2001.

The University of Notre Dame has a tradition of inviting new presidents to speak at graduation. But this year's selection of President Obama has been met by a barrage of criticism that has left some students fearing their commencement ceremony will turn into a circus.

Many Catholics are angered by Obama's planned appearance at the May 17 ceremony because of his decisions to provide federal funding for embryonic stem cell research and international family planning groups that provide abortions or educate about the procedure.

The consensus this week on the campus of the nation's most-prominent Catholic university was that any president should be welcomed.

"People are definitely entitled to their outrage, but I think the main thing is to see that it's an honor to have the president of the United States come to speak here whether you agree with him or not," said Katie Woodward, a political science junior from Philadelphia.

Justin Mack, a senior film major from Dallas, agreed.

"I didn't vote for him and there are a lot of things I don't agree with him or support. But I feel like for this event, people need to put that aside," he said. "My hope is that doesn't distract too much from what the weekend is about, which is the graduation."

But the distractions have been mounting, including sharply worded letters from two bishops. Bishop Thomas J. Olmsted of the Phoenix Diocese on Wednesday called Obama's selection a "public act of disobedience" and "a grave mistake." On Tuesday, Bishop John D'Arcy of the Fort Wayne-South Bend Diocese, which includes Notre Dame, said he would not attend the ceremony because of Obama's policies.

Hundreds of people on both sides of the issue have sent letters to the student newspaper, and a coalition of conservative student groups has announced its opposition.

University spokesman Dennis Brown says Notre Dame does not plan to rescind the invitation. Anyone associated with the university can recommend a commencement speaker, he said, and the president consults with university officers to see who would be most appropriate.

Notre Dame President the Rev. John Jenkins has said the university does not condone all of Obama's policies but that it's important to engage in conversation.

White House press secretary Robert Gibbs said Thursday that Obama believes everyone has the right to express their opinion, saying the president met last week with Chicago Cardinal Francis George and others to discuss topics Obama and the Catholic church are interested in.