Perhaps Clinton was excluded because of his stance on abortion. As retiring Notre Dame professor Ralph McInerny and WSJ columnist William McGurn note, Obama's position on life issues ("safe, legal, and government funded"?) has certainly not disqualified him.
The University promises a dialogue, to engage him. The President likes dialogues, but only when others are open to being persuaded by him. Certainly the most prominent lectern in American Catholic higher education is a bully pulpit, so to speak. I predict that his approach will not be much different from that of his predecessor, John F. Kennedy, speaking at Boston College, who gave lip service to the diversity of American higher education but ultimately urged subordination to national goals, quoting Woodrow Wilson to this effect:
"It is not learning," said President Wilson, "but the spirit of service that will give a college place in the public annals of the Nation." "It is indispensable," he said, "if it is to do its right service, that the air of affairs should be admitted to all its classrooms... the air of the world's transactions, the consciousness of the solidarity of the race, the sense of the duty of man toward man . . . the promise and the hope that shine in the face of all knowledge .... The days of glad expansion are gone, our life grows tense and difficult; our resource for the future lies in careful thought, providence, and a wise economy; and the school must be of the Nation."
As The President has reminded us in other contexts, he wants all hands on deck...so long as he's the one steering the ship.