Magnes returned to the United States in April 1948 to participate in an anti-partition campaign. When he left, his position at Hebrew University was in jeopardy, as more staff moved against him due to his views. According to Israeli historian Benny Morris, the Hadassah medical convoy massacre of April 13, 1948, was "in effect the final nail in the coffin of Magnes' binationalism. It was not that he publicly recanted. But he understood that it was a lost cause - and that his own standing in the Yishuv had been irreparably damaged." At the funerals of the victims, eighteen staff members from Hebrew University signed a petition protesting Magnes' view. The campaign was led by Professor Shimon Fritz Bodenheimer, who called Magnes a "traitor".