(NEW YORK) -- The semi-controversial HBO political movie Game Change that documents John McCain's unsuccessful presidential campaign in 2008 -- particularly his choice of Alaska Gov. Sarah Palin as his running mate, premieres Saturday night at 9:00 p.m. ET.
A number of Palin confidantes have claimed that the movie is inaccurate. Still, Game Change star Julianne Moore says she strived to make her portrayal of Palin true to life.
She says, "It's a daunting task to play somebody who is not only a living figure, but a hugely well-known one. So for me the most important thing is accuracy."
To that end, Moore says she hired a vocal coach to help her with the role because Palin "has an incredibly idiosyncratic way of speaking."
At Thursday's premiere of the movie in Washington, D.C., Moore addressed the pro-Palin critics who've commented on the project.
She said, "With every movie of book or whatever, people are always going to have an opinion. Obviously people are entitled to whatever opinion they're gonna hold, but I do think that they should see the movie first."
Ed Harris plays McCain in Game Change. He says he has a greater appreciation for the Arizona senator after doing research for the movie.
"I spent a lot of time reading some of the books that he'd written. He's a man of tremendous sense of honor and duty," Harris said.
Game Change, based on the book of the same name by Mark Halperin and John Heilemann, also stars Woody Harrelson, Ron Livingston and Peter MacNicol.
Copyright 2012 ABC News Radio