Admittedly, I haven't seen How Arnold Won the West yet, but had a question about your review of it. For instance, your accusation of its metaphor of David and Goliath being amiss seems either blinded, because of a lack of documentation on your part, or else because there isn't documentation to be had. By the film, Schwarzenegger could be Goliath, and you haven't said why it couldn't be without an apparent disregard for the effort of people who made their statement within this movie.
My own opinion of Gray Davis is that he's an honorable person, as he's able to speak with credible coherence and I have no reason to believe he isn't honorable. It's Schwarzenegger who has never proven himself in a political realm, yet he's entered into a political field where the only thing we know of Schwarzenegger is that he's an action-movie actor with a big box-office draw. It's more likely that the Republican party is using his reputation to garner partisan support, as this is typical, as it has employed many people with unstable reputations in politics, like the fired Marine Lieutenant Colonel Oliver North or actor Ronald Reagan. Or, its supporters have had doubtable interests like histories of anchoring neo-conservative partisanship as fundamentalists, like actor Charleton Heston who headed the NRA.
Furthermore, I would believe that someone British would have something to say about Governor Schwarzenegger as, like the rest of the world, the people who think the U.S. acted unethically in its invasion of Iraq, the British who had been drawn into it by certain government officials' connections with the Bush Administration, are in the majoirity; and so, I certainly expect some Americans to come forth defending their neo-conservative icon, Arnold Schwarzenegger, without considering first his objectivity and without a keenness to his platform, as this is what makes neo-conservatives neo-conservative. And, because the ratio of supporters of the Iraq invasion and occupation is much higher in the U.S., which is consequently the very reason Bush could ever get elected, let alone Arnold.
There is one distinction from your questioned metaphor though: David knocked down Goliath; but, Gray Davis, with all his knowledge, still lost to Arnold.
This only insinuates metaphorically that Goliath defeated David.