At a congressional hearing on Tuesday, the leaders of Harvard, the University of Pennsylvania and the Massachusetts Institute of Technology gave carefully worded — and seemingly evasive — answers to the question of whether they would discipline students who called for the genocide of Jews. The intense criticism that followed led many to wonder: Who had prepared them for testimony? It turns out that one of America’s best known white-shoe law firms, WilmerHale, was intricately involved. Two of the school presidents, Claudine Gay of Harvard and Elizabeth Magill of Penn, prepared separately for the congressional testimony with teams from WilmerHale,...