The new documentary "The U.S. vs. John Lennon," now playing nationwide, tells the story of Lennon's transformation from loveable moptop to anti-war activist, and recounts the facts about Nixon's campaign to deport him in 1972 in an effort to silence him as a voice of the peace movement.

In the film, Walter Cronkite explains that J. Edgar Hoover "had a different conception of democracy" from the rest of us; George McGovern talks about losing the 1972 election to Nixon; Sixties veterans Angela Davis, Bobby Seale, John Sinclair and Tariq Ali recall their movement days; and G. Gordon Liddy happily explains the Nixon point of view: Lennon was "a high profile figure, so his activities were being monitored."

Those "activities" – planning a concert tour that would combine rock music with antiwar organizing and voter registration for the 1972 election – were stopped cold by Nixon's deportation order; but more than 30 years later, in the 2004 election, another group of rock stars finally did exactly what Lennon had been thinking about doing.

Although the Lennon film never explicitly connects the Vietnam war to Iraq, it's impossible not to think of the present when Nixon is shown saying, "as South Vietnamese forces become stronger, the rate of American withdrawal can become greater" (and then wipes sweat off his upper lip). But there's only one explicit reference to the present in the film, and it's brief: Gore Vidal says "Lennon represented life, and Mr. Nixon, and Mr. Bush, represent death."

The real star of the film of course is Lennon, whose biting wit shines through. On his way to his deportation hearing, a newsman says, "You say you've been in trouble all your life – why is that?" "I'm just one of those faces," he replies; "people never liked me face." (I worked on the film as historical consultant, and appear in it briefly.)

Nixon got the idea of deporting Lennon from an unlikely source: Strom Thurmond, Republican Senator from South Carolina, who sent a letter to the White House in 1972 that outlined Lennon's plans for a US concert tour that would combine rock music with antiwar organizing and voter registration. Thurmond knew that 1972 was the first year 18-year-olds were given the right to vote, and that Nixon, up for reelection, worried about 11 million new voters — who were probably all Beatle fans and mostly anti-war. Thurmond's memo observed that Lennon was in the U.S. as a British citizen, and concluded "deportation would be a strategic counter-measure."

It worked; the Lennon tour never happened.

For the next 30 years, the idea of a tour combining rock music and voter registration languished, until 2004, when Bruce Springsteen and a group of activist rock musicians did an election year concert tour of battleground states with a strategy very much like Lennon's. The "Vote for Change" tour, organized by MoveOn PAC, brought the Dixie Chicks, R.E.M., Pearl Jam, and a dozen others on a tour of swing states, with the explicit goal of getting young rock fans to register to vote and vote against the Republican in the White House.

If the idea of using rock concerts to register young voters was the same, the 2004 tour had different politics from its 1972 predecessor – that much is clear from the one concert Lennon did do before the deportation order came down: the "Free John Sinclair" concert in Ann Arbor in December, 1971. Sinclair was a Michigan activist who had been in prison for two years for selling two joints of marijuana to an undercover cop; 15,000 people turned out for the concert. "The U.S. versus John Lennon" features footage from that concert, including wildly radical speeches by Jerry Rubin, and Bobby Seale, who said "the only solution to pollution is a people's humane revolution!"

The Vote for Change tour had much less political talk, and much milder rhetoric. On opening night in Philadelphia in October, 2004, Bruce Springsteen made only a brief political statement: "We're here to fight for a government that is open, rational, forward-looking and humane," he said – not quite the same as Jerry Rubin at the 1972 concert shouting "what we are doing here is uniting music and revolutionary politics to build a revolution around the country!"

The 2004 effort was much bigger and better organized than what Lennon had in mind. It included thirty-three concerts on a coordinated schedule that moved from battleground state to state. On opening night a month before election day the focus was Pennsylvania. Springsteen played in Philadelphia, the Dixie Chicks played Pittsburgh, Dave Matthews did State College, Pearl Jam was in Reading, John Mellencamp in Wilkes-Barre and Jackson Browne and Bonnie Raitt in Erie. The next night they all moved to Ohio, then Michigan, Wisconsin, Minnesota, Iowa, Florida, and then a giant finale brought everyone together in Washington, DC.

Of course 1972 and 2004 ended the same way – with the re-election of the Republican incumbent. In '72, Nixon won by a landslide; in 2004, Bush barely won the popular vote – you might call that progress.

One factor has remained the same over the last 35 years – young voters are the least likely to vote, and potentially a rich source of progressive support. The challenge of overcoming their apathy and ignorance remains – as does the strategy of reaching them through music. Thus what Lennon thought about in 1972, and what Bruce Springsteen, the Dixie Chicks and others did in 2004, remains a key to mobilizing young voters in the future.

As Lennon says in "The U.S. vs. John Lennon," "our job now is to tell them that there still is hope, we must get them excited about what we can do again."