Presidential look-alike Kevin Kline is asked to pose as the president by chief of staff Frank Langella in this dumb but likable Capra-esque comedy directed by Ivan Reitman from a script by Gary Ross. The movie remystifies as much as demystifies presidential politics, but an overall mood of sweetness may help one to forgive the archaic and childish aspects of the would-be analysis, which splits everyone between angels and devils. Also starring Sigourney Weaver, as the first lady. With Kevin Dunn, Ben Kingsley, and Ving Rhames, and in cameos a host of Washingtonians and media personalities, including Senator Paul Simon, appellate judge Abner Mikva, Larry King, and Oliver Stone. (JR)