This film definitely comes from a viewpoint that Cheney and Rumsfeld had a net negative effect on the country and the world. It's a viewpoint that matches mine, but looking at McKay's remarks that the film can really be watched by anyone, I think he's either optimistically blinded or saying that purely for the purpose of publicity.

I don't know if impartiality is always such a noble objective in politics, or at least political media. There's this assumption that between two viewpoints the truth lies, when that is not always the case. It's a bias that always ends up favoring conservatives because conservatives have - ever since the Nixon days - much, much less restraint on the awful things they're willing to say and do to maintain power. If one supported Bush and Cheney to their worst lows, a/or supports Trump, who is constantly finding new lows... what film is going to be impartial enough? What's the likelihood of any film, no matter how impartial, changing one's mind? How many facts, surveys, polls must be cited before "fake news," "lies," "liberal bias" stops being chanted, drone-like, every time reality gets a mention? Nothing will satisfy them. Nothing.

TL;DR: Impartiality doesn't matter too much to me, at least in Hollywood, because "impartiality" usually equals conservative bias.

IN ANY CASE though you are correct that it is not impartial and that it does preach to the choir. I probably should spell that out explicitly in my review, instead of leaving it implicit. I have revised the 'Concluding Thoughts' section to make that explicit.