The man at the bar looked familiar, even before he started telling anyone who would listen how George W Bush had spent millions of dollars to prevent him becoming President of the US. It was more interesting than going to a lecture on the mating habits of Galapagos fauna, which was the only other entertainment available on a cruise ship in the Pacific Ocean, and it didn't take long to work out that our disgruntled fellow-passenger was the Arizona senator, John McCain.
We spent the next few days with McCain, clambering in and out of small boats to reach deserted islands where marine iguanas and sea lions basked in the sun, and his interest in the endangered archipelago seemed genuine. I wasn't surprised, a couple of years later in 2003, when McCain came out against Bush's plan to allow drilling for oil in a wildlife refuge in Alaska.
Unlike some fellow-Republicans, he accepts that climate change is real and caused by man-made emissions. "We are convinced that the overwhelming scientific evidence indicated that climate change is taking place and human activities play a very large role," he said during a visit to Barrow, America's northernmost city, in 2005.
At the time, McCain and a Democratic Senator, Joe Lieberman, were sponsoring legislation to limit greenhouse gas emissions from industry, pitting McCain against sceptics in his own party, who blame the earth's warming on natural cycles. It is this willingness to question Republican dogma, along with the testiness I glimpsed in the Galapagos Islands seven years ago, which led to McCain being described as a maverick long before he confounded commentators by emerging as the Republican front-runner in this year's Presidential contest.
On other issues, such as gays in the military and abortion, McCain is a conventional right-winger. But there is something that marks him out from all the other candidates in the race to succeed Bush, including Hillary Clinton and Barack Obama, whose struggle-to-the-death for the Democratic nomination looks likely to realise the Republican senator's dream of replacing his old rival in the White House.
Last weekend, as Clinton and Obama shamelessly vied for evangelical votes at a Christian forum in Pennsylvania, McCain was absent, underlining the fact that he doesn't do God – not in public, at any rate. In a campaign notable for the nauseating religiosity of the other candidates, McCain had the guts to turn down an invitation to speak at the forum, saying that his religious faith was intense but private. Like the protagonist of Richard North Patterson's latest novel, The Race – a war hero whose experience of captivity bears a striking resemblance to the torture McCain endured in Vietnam – McCain simply doesn't feel comfortable talking about his relationship with Jesus.
This has infuriated religious conservatives, who have been engaging in hilarious discussions on websites about whether McCain is entitled to attend a Baptist church when he hasn't undergone a full-scale emersion; Southern Baptists like to see everyone get in the tank and McCain's failure to get water-logged has fuelled suspicions that he's still an Episcopalian. They're hoping that the Senator will be forced to do a U-turn and speak openly about his faith before the election in November, contrasting his silence unfavourably with the extravagant expressions of faith made by both Democratic hopefuls.
Incredible as it seems, with a hugely unpopular evangelical President in the White House, this time it's the Democrats who have got God, and they go on about it at a length which would have British audiences screaming for the sick bag.
Sadly, there is no evidence for the theory put forward by worried Democrats that either candidate's religious fervour is tactical. When Clinton published her autobiography, Living History, five years ago, she included a picture of herself with her "prayer group" enjoying a "cookout" in 1993. That was the year, according to the radical magazine Mother Jones, in which Clinton became "an active participant in conservative Bible study and prayer circles that are part of a secretive Capitol Hill group known as the Fellowship", a network of political, business and military leaders dedicated to "spiritual war" on behalf of Christ.
Warlike metaphors pop up in her rhetoric, such as the occasion last summer when she attended a forum hosted by an evangelical Christian group called the Sojourners and was asked how her faith had helped her get through the scandal caused by her husband's affair with Monica Lewinsky. Without missing a beat, Clinton was off, thanking "people whom I knew who were literally praying for me in prayer chains, who were prayer warriors for me".
Notions of sin, struggle and redemption inform her language to an extraordinary degree, prompting her to write about a post-Lewinsky "prayer breakfast" with religious leaders at the White House, at which her husband "offered an emotional admission of his sins and a plea for forgiveness from the American people".
Democrats who dislike this stuff as much as I do can't take much comfort from Obama, who asked a church audience in Bible-Belt South Carolina to help him become an "instrument of God" and join him in creating "a Kingdom right here on earth". In recent weeks, Obama has tried to distance himself from a controversial black pastor, the Rev Jeremiah Wright Jr, whose divisive views about race have been given a wide airing; the candidate is visibly irritated these days by suggestions that Wright was his mentor.
But the fact remains that the pastor officiated at Obama's wedding and it was in his Trinity United Church of Christ on the Southside of Chicago that Obama, once a sceptic like his parents, committed himself to God in the 1980s: "Kneeling beneath that cross on the Southside, I felt that I heard God's spirit beckoning me. I submitted myself to His will, and dedicated myself to discovering His truth".
This is the kind of stuff right-wing Christians hope to hear when they claim that American voters "want a sense of where someone stands in their relationship with the Lord". Against this background, McCain's refusal to give in to evangelical bullying is refreshing: "I think it's something between me and my creator. It's primarily a private issue rather than a public one," he told an interviewer last year.
It says something about the current state of US politics that the only Presidential candidate who is willing to uphold the separation between church and state is a Republican, and the choice between two supposedly radical politicians who don't appear to understand its importance is no choice at all. The Democrats are letting down millions of people who are secular if not actually agnostic, all of whom have votes even if they make less noise than the religious right. I'm not quite rooting for McCain, but I've had more than enough of Clinton and Obama banging on about their imaginary friends.
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