HBO Films seems to have two essential mission statements. First, to corner the market on Al Pacino’s good acting (see: Angels in America, You Don’t Know Jack, the upcoming Phil Spector biopic. Second, and more importantly, the moviemaking arm of the network appears to be constructing a complete chronology of American history, from the Revolution (John Adams) through the Great War (Band of Brothers, The Pacific), and right up to our disturbing modern moment (Recount, Too Big to Fail). Next year’s Game Change is an intriguing new entry in the HBO History canon, adapting the addictive behind-the-scenes muckrake of the...