Richard Nixon, no less than David Frost, was a TV personality. Every U.S. President from John Kennedy on has had to be one: the nation's talk-show host, defining its agenda and character. Nixon's four-part interview with Frost in 1977, three years after he left the White House in disgrace, was a meeting of two brilliant, compromised men with something to prove: Nixon that he was a statesman, not a crook; Frost that he had the gravitas to bring a big man down. The Ron Howard movie of Peter Morgan's docuplay keeps the play's stars — Frank Langella as Nixon, Michael Sheen as Frost — and buttresses the confrontation with news clips from the Watergate years. What was a pageant on the stage becomes an intimate, magnified TV show, the closeup camera alert to every nuance of Frost's insecurity rising to bravado and Nixon's pugnacity gradually sagging into defeat. This very fine movie doesn't make history, but it captures history as few others have. 12/5