When Columbia’s president, Nemat Shafik, testified, Representative Elise Stefanik of New York singled out Mohamed Abdou, an assistant visiting professor. Ms. Stefanik quoted from one of his posts on Facebook, under a different spelling of his name, supporting Hamas, Hezbollah and Islamic Jihad four days after the Oct. 7 Hamas attack on Israel.

“What are the consequences in this case?” Ms. Stefanik asked.

“He will never work at Columbia again,” Dr. Shafik replied.

Dr. Abdou’s contract was not renewed, and he is suing Dr. Shafik and the university for defamation and “loss of academic freedom,” among other complaints.