By Alicia M. Cohn - 03/06/12 02:18 PM EST
"Everything was sourced," Moore said on MSNBC's "Morning Joe," saying
she often went back to the original material — speeches, interview
transcripts — seeking "veracity."
"I cannot presume to know her — I don't," Moore said. "[But] when I was doing my research I spent a lot of time looking at her own material; I read her book, her speeches.
Both Sen. John McCain (R-Ariz.), the 2008 GOP presidential nominee, and his vice presidential pick, the former Alaska governor, have said they will not see the film. Both have criticized the book it was based on, 2010's Game Change by journalists John Heilemann and Mark Halperin.
McCain earlier this week called the book "totally unfair and untrue, especially to Sarah Palin."
Palin warned supporters of the movie's "distortions" in a fundraising email this week.
But Moore and "Game Change" director Jay Roach called the book meticulously researched.
"[We] committed to tracking down all the sources, as many as we could that these guys [the authors] used, and confirming that they weren't messing around," Roach said. "We don't have to make anything up because it's so compelling, the predicaments that all of them found themselves in."
He added that "there are really no heroes or villains in this story."
"Game Change" premieres on HBO March 10.