KEY POINTS:
It is early but the candidate is, as on most days recently, already far down the path of hyper-caffeination, repeatedly tensing his torso, pacing back and forth on the stage.
His arms, which he cannot raise above his shoulders because of injuries sustained when he was tortured in North Vietnam, rarely rest and nor do his fingers. John McCain has distractingly fiddling fingers.
"My friends," he begins, as he has almost every speech on the campaign trail since mid last year, "I have some straight talk for you."
Some time later, he exhorts: "I am going to tell you, and look you in the eye, my friends."
You might think, as the out-and-out favourite to win the Republican nomination race, he would be more relaxed. If the polls and pundits are correct, this may be the day when the dream that McCain saw thwarted eight years ago - thanks to vicious attacks by his foe at that time, George W. Bush - finally comes true.
It is the day in the US when more than 20 states get to help select the nominees of both parties and, while nothing may be resolved on the Democrat side, McCain may be poised to win enough delegates to declare himself the Republican victor.
A couple of days ago, he was rapped by the media for daring publicly to predict he was about to win and see off his last serious rival, Mitt Romney. By campaigning in Boston yesterday - in the shadow of the State House that Romney until recently presided over - he seemed to be conveying some of the same cockiness. But inserting thorns in other people's sides seems to come naturally to McCain. He does it to his own party all the time.
Many mainstream Republicans will have to dig deep in their souls to muster support for him if he becomes the nominee. If he is often labelled a maverick - even idiosyncratic - it is because he has never hesitated to go against the grain of party wisdom on subjects ranging from immigration and global warming to gay marriage and campaign funding.
No wonder he has found himself excoriated on America's airwaves - even in recent days by the likes of the radio talk-show host Rush Limbaugh, who said McCain would "destroy" the party if nominated and the commentator Ann Coulter who let it be known that she would rather vote for Hillary Clinton if he takes the nomination.
Because he is a bruiser in the Senate chamber and because he has always had trouble not becoming personal when fighting his political battles, the Arizona senator finds himself also disliked by some senior colleagues on Capitol Hill.
"The thought of his being President sends a cold chill down my spine," was the response of Senator Thad Cochran of Mississippi. "He is erratic. He is hot-headed. He loses his temper and he worries me."
But if he wins the nomination, McCain will also essentially take the flag of the party from Bush and establish himself as the de facto leader of the Republican Party, possibly for years to come. His foes, therefore, had better swallow their feelings, and quickly.
After McCain began winning crucial contests in the primaries - first New Hampshire and then South Carolina and Florida - most Republicans began to rally behind him for the simple reason that he appeared the most electable of all their party's runners. More than that, polls showed that only he stood any serious chance of beating a Democrat in November.
The media have filled his sails too, because his story, after all, is remarkable. It began with his doomed mission over the skies of Hanoi in 1965 when he was shot down. He survived but spent 5 1/2 years in captivity and suffered terrible physical abuse.
That, of course, is part of what makes McCain a natural hero to so many American voters. It is also the bedrock of his reputation as by far the strongest of the Republican candidates on matters of national security and foreign policy.
If there is a danger in this, it is that McCain sometimes gives the impression that these are the only topics he likes to talk about. He did make brief reference to the economy here in Boston too but, as usual, he lingered far longer on what he likes to call the "transcendent challenge of our times - radical Islamic extremism".
You do not have to dig too far into McCain's record to find examples of him flame-torching his own colleagues. He once accused the current Senate Minority Leader Mitch McConnell of trying to stave off legislation harmful to the tobacco industry because of the generous donations it gave to Republican legislators. He has been heard to throw curse words at another senator for apparently failing to do his homework properly on immigration legislation and to accuse another of "egregious behaviour" in connection with a particular defence contract.
On the stump even now, one of his favourite themes is the habit of colleagues - from both parties - to attach so-called pork-barrel earmarks to spending bills, designed to funnel federal money to pet projects in their own states. The most famous case he always mentions is "the bridge to nowhere" - US$30 million ($38 million) engineered by Ted Stevens, the Republican senator from Alaska, for a bridge to an island with 50 inhabitants. On this and other issues you glimpse that passion that can put fear into others back in Washington.
Here in Boston, he conjures the word "evil" twice, once in connection with Islamic terrorists and Osama bin Laden - "If I have to follow him to the gates of Hell I will get Osama bin Laden and bring him to justice" - and the second time on the plague of earmarks, which in the past two years, he claims, have cost US taxpayers US$35 billion. "When that kind of spending goes on, it breeds evil."
In 2000, questions about his temperament stalked him everywhere until his campaign crashed. In 2008, all that crustiness has been part of what has recommended McCain to voters. He has little eloquence and resorts to a teleprompter for speeches on big nights. But McCain shows himself accessible and eager to engage. He has frequently found himself locked in debate with a single audience member for as long as it takes to get whatever issue it is settled. He is similarly open to debating with reporters.
The lucky penny he keeps warm in his left-hand trouser pocket should not be set aside today but mounted in a silver frame to be hung one day - well, who knows? - on the wall of the Oval Office. But as the likely nominee McCain knows he will come in for intense additional scrutiny.
In the coming days he will set out a new economic programme, but critics (including Romney) continue to contend that as the American economy shows signs of an imminent slump, McCain has little expertise or experience to handle it. He has acknowledged the economy is not his strong suit. Nor, best we can tell, is health care or education.
Even on foreign policy, there are areas where additional examination may be called for. When questioned what the US should do, McCain adapted the Beach Boys classic anthem Barbara Ann, answering: "Bomb Iran. Bomb bomb bomb bomb bomb ... Iran." And then there's Iraq.
His support for the surge was one of the factors that all but sank his campaign almost before it had started. Today, with at least a relative decline of violence in that country, McCain trumpets the decision he made, saying repeatedly that he "would rather lose an election than lose a war".
Yet, the Democrats will want to examine his earlier record on Iraq, embedded with the Neocons, arguing for regime change in Iraq even before 9/11, and insisting on the existence there of weapons of mass destruction.
No one can predict what will happen exactly. But what we can say is this: The first two words of the speech he gives tonight will be: "My friends."
- Independent
