Rudenstine has also reportedly declined to become a candidate for the presidencies of a number of other universities. In fact, in 1987 he told the Daily Princetonian, the Princeton student newspaper, that he had no desire to be the president of any university.

He explained to the newspaper that he did want to give up what he enjoys-humanities and the arts-to assume "external" responsibilities such as fundraising and relations with the government, other universities and alumni "an enormous number of things to which the president simply must give his time."

"My own assessment, quite honestly, is that those tasks on the outside are those that I would be less good at. They are less close to my heart," he said.

Indeed, some observers say it is hard to discern Rudenstine's accomplishments as provost from those of former Princeton President William Bowen.

And some say Rudenstine's decision to leave academia and follow Bowen to the Mellon Foundation could hurt his chances at getting Harvard's top post.

Similarly, Breyer's decision to leave his professorship at the Law School to accept an appointment to the circuit court could be a drawback.

And although both Hood and Casper have distinguished records in their academic fields and in university administration, neither has spent any time at Harvard, whether as a student or as a professor.

While McElroy is a popular department chair and teacher, he is considered by some to be an unlikely choice because he was raised and educated in Ireland. Similarly, Knowles was born in England and attended Oxford University. He also reportedly turned down the FAS deanship in 1984