He never supported Pol Pot. I do not understand why everybody keeps saying that and keeps relying solely on those who have no evidence to support that position. Let's go the source: I have the book Manufacturing Consent in front of me. I have used it on a few occasions for two research projects and am pretty familiar with its contents. I have emailed him directly regarding this book, too.
So, with the book in front of me, I will quote the one statement that has everybody's dicks hard for hating Chomsky: "The victims of Pol Pot, a Communist leader, were worthy, although after he was ousted by the Vietnamese in 1978, Cambodians ceased to be worthy, as U.S. policy shifted toward support of Pol Pot in exile. The East Timorese remained unworthy in the 1990's, as the table suggests." So, without reading the book, you would think he's talking about worthy and unworthy the way that we normally mean it. However, he munificently describes the difference: "Our prediction is that the victims of enemy states will be found 'worthy' and will be subject to more intense and indignant coverage that those victimized by the United States or its clients, who are implicitly 'unworthy'."
But, it's a lot easier for all of you with single digit IQ's to look up secondary-source material like Wikipedia which is essentially a mashup of opinions and has never been considered a reliable academic medium. No book or publication can ever be sourced by Wikipedia yet you all do this all day long.
Manufacturing Consent is not an easy read, but if you would actually read the entire thing you would understand that he never even closely supported Pol Pot.