The Arizona senator's political and personal life is an open book. He has been described as "an extraordinarily uncharismatic" candidate running against the "extraordinarily charismatic" freshman senator from Illinois.

McCain, however, is a much-decorated Vietnam War hero, unlike Obama who has never before experienced the travails of war. McCain's political career has been based in large measure on his war record. As a Navy pilot, he was shot down over Hanoi in 1967, endured torture in prison camps, and even turned down a Vietnamese offer to release him because of his status as the son and grandson of four-star generals.

After his return from Vietnam in 1973, he wrote about his ordeals in "Faith of Our Fathers," a book that catapulted him to the House in 1982 and the Senate in 1986. In 2000, McCain sought the Republican presidential nomination, but after a heated contest he was defeated by then Texas Gov. George W. Bush, the only one race McCain lost in his political life. Now he is running for president, again.

When he was in the Senate, with his engaging personality and willingness to buck his party on occasion, he earned a reputation as something of a maverick. And if elected, he would be the oldest incoming president at the age of 72.

Political forecasters now say that McCain faces long odds because he has been repeatedly allied with Bush, the most unpopular president in the history of US politics. But polling strategists say McCain can still overcome all the problems stacked against him and pave his way to 1600 Pennsylvania Avenue in Washington, D.C.

"The path to success for McCain," they point out, "is to make the election a referendum on Obama by painting him as different, foreign, dangerous, and that he's black!"

That's a low road, of course, but they'll make sure the attacks won't come from McCain. The effort to make the campaign about voters' unconscious fears of Obama has already begun. They have been insidiously setting up Obama as "not one of us" and reminding Americans of Obama's "elitist" comments about average Americans as well as his wife Michelle's gaffe about being really proud of her country "for the first time."

Actually, Obama has been the target of a concerted smear campaign that he is a Muslim, that he refused to put his hand over his heart in reciting the Pledge of Allegiance, and that he took his oath of office in the Senate with his hand on the Koran. As early as 2006 conservative television talk show hosts were calling him "B. Hussein Obama," images on the Internet were morphing Obama into Osama, and commentators were raising questions about his patriotism.

"The pattern is clear," as Drew Westen, professor of Psychology and Psychiatry at the Emory University, said. "The goal is to portray Obama as 'them, not us.' And if anyone does not remember the term 'Black Muslim,' with all its associations . it is unconsciously active in all our minds."

However, more objective political observers say that Obama can steer clear of the smear campaign. He can fuel his presidential bid with "hope," which is deliberately at the center of his political strategy, something that he wrote about in his book "The Audacity of Hope," leading to his decision to run as the first black candidate for the presidency. To be sure, according to conventional wisdom, nothing helps hope like luck.

What then is the difference between McCain and Obama?

The answer may be found in Richard Cohen's column in the Washington Post. "McCain is a known commodity," he wrote. "It's not just that he's been around a long time and staked out positions antithetical to those of his Republican base. It's also - more important - that we know his bottom line. As his North Vietnamese captors found out, there is only so far he will go, and then his pride and sense of honor takes over. This . is what commends him to many journalists.

"Obama might have a similar bottom line, core principles for which, in some sense, he is willing to die. If so, we don't know what they are. Nothing so far in his life approaches McCain's decision to refuse repatriation as a POW so as to deny his jailors a propaganda coup. In fact, there is scant evidence that the Illinois senator takes positions that challenge his base or otherwise threaten him politically.

"A presidential race is only incidentally about issue. It's really about likability and character. Obama is more than likable enough. so much so that he is the most charismatic presidential candidate I have seen since Robert F. Kennedy (who was assassinated while campaigning for the presidency). But the character question hangs - not because of any evidence to the contrary and not in any moral sense, either, but because he (Obama) is still young and lacks the hob references McCain picked up in a North Vietnamese prison. McCain has a bottom line. Obama just moved his."

Still and all, if American voters come to see the race between McCain and Obama as between conventional politicians, some say, McCain will probably win over Obama, if it becomes a race between a "white" candidate and a "black" candidate.

Well, one can very see that the presidential contest this coming November will be the nastiest and most racist in modern American political history.

Will John McCain win the US presidency that way?