By Rich Heldenfels
McClatchy Newspapers

If you need another demonstration of the star power attached to Sarah Palin, look no further than “Game Change,” the movie airing on HBO at 8 p.m. Saturday.

The film chronicles Palin’s role in the 2008 presidential campaign, where she was plucked from the relative obscurity of the Alaska governorship to be John McCain’s vice presidential running mate. Julianne Moore plays Palin — marvelously, by the way — with Ed Harris as McCain and Woody Harrelson as McCain adviser Steve Schmidt. The production also includes real news footage of some Palin events, with Moore edited in.

Scripted by actor-writer Danny Strong (“Recount”), “Game Change” is based on the book of the same name by Mark Halperin and John Heilemann. But the book dealt with both sides in the 2008 campaign, including the long conflict between Barack Obama and Hillary Clinton in pursuit of the Democratic nomination for president.

The McCain / Palin saga doesn’t even begin until the book is about half done; still, the filmmakers (among them director Jay Roach, also of “Recount,” and executive producer Tom Hanks) have opted to focus on the Palin story.

Of course, it’s a good story, and she became a major figure on the national stage regardless of what you think of her politics. “Game Change” is relatively faithful to the book, and like the print account it makes clear that Palin was chosen hastily and without the vetting that had accompanied other contenders.

And she was exactly what the campaign wanted, at least on paper: more conservative than McCain’s first choice, Joe Lieberman (played here by Austin Pendleton), and so more attractive to many Republicans; a very effective speaker and, at least for a time, a game changer for the Republicans trying to match Obama’s dramatic rise.

To be sure, the movie shows Palin as preparing poorly at key moments, but that’s part of the record. “Game Change’s” problems are less about what Palin does than in how the film as a whole works.

As good as the acting is, the movie feels very careful, as if it was written and produced with the awareness that Palin would have lawyers checking every scene. So we don’t get very far into the inner life of Palin, offered instead her behavior and the perceptions of people around her. (It’s pretty clear which characters were major sources.) As viewers, then, we do not get much more than what we already knew.

Besides, the Obama-Clinton campaign was a much better story.