REVIEWED - THE ASSASSINATION OF RICHARD NIXON: SAMUEL Byck seemed to be relegated to a footnote in American history until a year ago this month when he was featured as a character in the Broadway revival of Assassins, Stephen Sondheim's musical juxtaposing and exploring the personalities of nine people, from John Wilkes Booth to John Hinckley, who attempted to take the life of an American president.

Three weeks later, at the Cannes Film Festival, Byck resurfaced as the troubled protagonist of Niels Mueller's underestimated and fascinating movie, The Assassination of Richard Nixon. We know from the outset that, while Nixon believed himself to be the victim of character assassination, he was not murdered. However, six months before Nixon was driven from office in August 1974, Byck attempted to kill him. Eerily anticipating the events of September 11th, Byck's plan was to hijack a jet plane and force the pilot to fly it into the White House. As with everything else in Byck's life - his marriage, his job as an office furniture salesman, his plan to run his own business - the plot failed.

Mueller's fictionalised dramatisation of these basic facts begins at the end and employs flashbacks to probe the psychology of Byck (whose surname is spelled Bicke in the film).

In Sean Penn's riveting, achingly honest and vividly detailed performance, Byck emerges as a mess of desperation, disillusionment and self-delusion - a cross between Willy Loman in Death of a Salesman and Rupert Pupkin in The King of Comedy, until he finally takes on intimations of Travis Bickle in Taxi Driver.

Wallowing in self-pity and deeply embittered at missing out on the American Dream, Byck sends a tape of his own story to the composer he most admires, Leonard Bernstein. It begins with Byck morosely stating: "I consider myself a grain of sand, one of 211 million in America."

His employer (Jack Thompson) extols Nixon as the greatest salesman of them all for having won the presidential election in 1968 and in 1972 on the same platform: to end the Vietnam war. The erosion of whatever self-esteem Byck may have possessed is set against radio reports of Nixon's own unravelling as news breaks of his role in the Watergate scandal.

In his thoughtful and assured directing debut, Mueller dispassionately observes Byck's inexorable disintegration as he singularly fails to learn anything from the required reading of his profession in that era, Norman Vincent Peale's The Power of Positive Thinking and Dale Carnegie's How to Win Friends and Influence People.