Two basic arguments were employed by those who defended Columbia’s invitation to Ahmadinejad. The first was a straw man–that he shouldn’t be “barred” from speaking at campus. But given that most critics weren’t calling for the NYPD to prevent Ahmadinejad from speaking, this was not the issue. The argument was not over whether Columbia had the right to invite him, but whether it was right to invite him.
The second defense was that by holding Ahmadinejad up to tough questioning, it would show him for who he was. But none of the absurd statements he made at Columbia gave us any better insight into what a lunatic he is than his past statements.
Meanwhile, via Michael Rubin I see this account of the speech from the official Iranian news agency, which includes the line, “The audience on repeated occasion applauded Ahmadinejad when he touched on international crises.” So, he clearly obtained the propaganda victory he sought at a time when he is losing popularity at home as a result of his economic policies.