(CNN)One of the year's best documentaries, "Boys State" presents a fascinating look at teenagers brought together for an exercise in government, which somehow manages to unerringly encapsulate partisan divisions in the US right now. An opening medley of past participants -- including Bill Clinton, Dick Cheney, Cory Booker, Rush Limbaugh and Supreme Court Justice Sam Alito -- only stokes curiosity about where these youngsters will be 30 or 40 years from now.