Husam El-Qoulaq is the "target of a vicious smear campaign" aimed at "discrediting and defaming those who dare challenge Israel's abuses against Palestinians," the letter says.
The resolution calls on the union and its parent, the United Auto Workers, to divest from Israeli companies and calls on NYU to close its program at Tel Aviv University.
Faculty members who signed the letter, which has generated criticism from some Africana studies professors, have declined to release their names for publication.