I never saw Heifetz play the violin, or Hogan hit a five iron, or Pavlova do a pirouette. But I’ve seen John McCain work a reporter.

And I knew I was seeing a master at the peak of his form.

Here’s what happens. The reporter – call him Joe – hops aboard McCain’s old campaign bus, the Straight Talk Express. He knows the Arizona senator’s well-known charms. He will not be seduced.

Chatting amiably, Joe asks about a Republican colleague. With ironic solemnity, McCain responds by describing his fellow senator with an anatomical epithet. Against his better judgment, Joe chuckles. (Never heard that from a presidential candidate before!)

He asks a probing question about Mc-Cain’s personal life – and the senator answers without hesitation, never asking to go off the record. (Is there nothing this guy won’t be candid about?)

Joe’s detachment is already crumbling when McCain offhandedly mentions a self-deprecating anecdote from his time “in prison.” The reporter knows the reference is to McCain’s years as a POW in Vietnam, back when Joe was sucking bong hits at Princeton. (Guilt, guilt, guilt …)

McCain asks Joe about his kids, by name, then recommends a new book he’s been reading – something unexpectedly literary (I.B. Singer’s short stories?) Seamlessly, he mentions an article Joe wrote – not last week, but in 1993!

The reporter has never voted for a Republican in his life. But he’s a goner.

Already he’s composing the first paragraph of his profile: “Rolling down a New Hampshire highway in his campaign bus – aptly dubbed the ‘Straight Talk Express’ by his ragtag band of admirers – maverick Republican Senator John McCain turns aside all suggestions that his lone struggle for the soul of the Republican party is a Quixotic …”

And so it goes: the McCain Swoon. I’ve seen it happen once, twice, half a dozen times. It’s happened to me. And it doesn’t happen just to reporters. Professional liberals have famously succumbed, too, making McCain the U.S. elite’s most – indeed only – beloved politician.

Now the romance is coming to an end. As McCain eyes the 2008 Republican presidential nomination, he’s scandalizing his left leaning admirers. The senator who once dazzled them by calling evangelical leaders like Jerry Falwell “agents of intolerance” has agreed to give the commencement address at Falwell’s Liberty University.

And it gets worse, if possible. McCain recently had kind words for South Dakota’s uncompromising anti-abortion law. He endorses the Iraq war with the enthusiasm of a team mascot. And this year he voted to extend the same Bush tax cuts he opposed (to heart-stopping acclaim) in 2003.

What’s going on? The standard explanation is that McCain is pandering to the right-wing base he needs for the nomination. That’s probably true – and, to his admirers, crushingly out of character. They prefer not to consider the possibility that, way back when, he was pandering to them, too.

McCain is not more cynical than other politicians, but he is craftier and more adroit. His keen eye for the main chance has been obvious since his 1981 political debut, when he moved to Arizona as a celebrated former POW and immediately began “district shopping.” When a safe Republican congressional seat opened up, McCain bought a house in the district and established residency within 24 hours.

McCain’s ambition, wrote his highly sympathetic biographer, Robert Timberg, “was whipped to a lather.” And beneath McCain’s humorous and plainspoken persona, the lather still foams.

For non-Republicans, the McCain Swoon was an act of faith – a blind belief that McCain, against mountains of contrary evidence, was secretly just like them. He was a vast, empty screen upon which they cast their fondest hopes and vanities.

Those mountains of evidence have at last become too large for even them to ignore. There is, for starters, McCain’s 25-year voting record, which has earned him high ratings from the National Right to Life Committee, the American Conservative Union and the Christian Coalition.

The anomalies that dazzle liberals – and lead reporters like Joe – to dub McCain a “maverick” carry important asterisks.

It’s true he called Falwell and other politicized evangelists “agents of intolerance” – but only after they actively opposed him in early 2000 primaries. His obsession with campaign finance reform, the all-purpose reform of good-government idealists, came only after his entanglement in the Keating Five influence-peddling scandals of the late 1980s.

Environmentalists may admire his moderate voting record on their issues, but they ignore his devotion to nuclear power, which most environmentalists abhor.

Now that the Swooners are disenthralling themselves, the McCain campaign may get interesting.

In a country that shows no tolerance for spending cuts, McCain plans to run for president as a budget-cutter who means it. At a time when the latest U.S. military adventure – the conquest and rebuilding of Iraq – looks problematic at best, McCain will run as a committed interventionist. And on social issues – the only issues, aside from Iraq, that arouse voter passions – McCain has proved himself rhetorically hesitant and uncomfortable.

The end of the Swoon may be the least of candidate McCain’s difficulties. In 2008, poor Joe will have to compose a new first paragraph for his McCain profile.

Mr. Ferguson is a columnist for Bloomberg News.