I just saw this film at the AFI Film Festival in Dallas, so I don't know where it will available for viewing to future readers of this comment.After the showing, the director Nicole Torre said that as she began meeting some of the Texas oil men in the film, she changed her attitude and recognized some of her own hypocrisy towards the subject. I say the film is challenging because it doesn't simply rubber stamp your liberal bias, Torre takes us on her own voyage of discovery. Rather than trying to fit the interviews into preconceived notions, she uses the interviews to show our history with the brutal honesty of the oilmen she's interviewing.And they are what make the film humorous, along with some judicious editing by Sean McAllen. Oilman Clayton Williams says "You've got to have a sense of humor about this business," and it's the Texas straight talking and sense of humor that helps make the film interesting to watch.In fact after a while you begin to wonder whether you might be watching an infomercial instead of a documentary directed by a liberal, but sticking with it helps you confront your own ignorance and hypocrisy, and begin to see the oilmen as allies rather than enemies.As a Texan I noted a curious turn take place about 2/3 of the way through - the accents changed from old-style Texas accents to modern, generic American accents. Watch the film to find out why.