For the second day in a row, graduates of Columbia University critical of its administration met the acting president, Claire Shipman, with a chorus of boos during her speech at the main commencement ceremony on Wednesday. It comes a day after graduates — who lived through campus lockdowns, the arrests of hundreds of students on campus and of Mahmoud Khalil, and a revolving door of university presidents — expressed anger at administrators, including Shipman, during smaller ceremonies. Read the