Traveling across the Pacific this week, McCain sounded as though he needed convincing - but not much.
``It's an incredibly grueling affair that requires a lot of sacrifice on the part of family,'' he said by phone from Honolulu. ``I wouldn't give it serious thought until after my reelection in 1998, and then it might be too late.''
But at the moment, in a party with no obvious leader, McCain looks like a reasonable prospect.
His stature was certainly not diminished when President Clinton phoned him two days after Election Day to chat about campaign-finance reform, a longtime passion of the senator's.
McCain, though, served notice that he will be no pushover. After speaking to Clinton, he said that bipartisan cooperation on the issue, if it comes, would not absolve Congress of the responsibility to examine the Democrats' dealings with foreign contributors.
The son and grandson of Navy admirals, the snowy-headed McCain, 60, is poised to take over the chair of the powerful Commerce Committee, a position from which his defeated predecessor, Larry Pressler (R., S.D.), raised more than $1.6 million from political action committees - more than any other senator.
McCain does not deny the attractive fund-raising potential of the post.
``I'll play under the rules as they are written,'' McCain said. ``But it won't diminish my zeal for campaign-finance reform.''
With Sen. Russell D. Feingold (D., Wis.), McCain has been pushing the first bipartisan campaign-finance reform bill in a decade. They plan to reintroduce the measure in January.
A leading defense hawk, McCain has nonetheless consistently skewered the pork in the Pentagon budget. He opposes the construction of a third Seawolf nuclear-powered attack submarine and additional B-2 bombers.
McCain's mutinies against the party line have made him some enemies.
In 1994, he refused to campaign in Virginia for GOP Senate nominee Oliver North, a fellow Annapolis grad, even though McCain was then vice chairman of the National Republican Senatorial Committee.
McCain took a lead role in advocating the reestablishment of economic and diplomatic relations with Vietnam - in defiance of Republican opposition.
He has also worked closely with Sen. John Kerry (D., Mass.), a veteran who opposed the Vietnam War, to bring closure to the POW-MIA issue.
Once the leader of a rowdy clique in the Naval Academy's Class of 1958, McCain has never been predictable. Nor has his political trajectory.
He spent nearly six years in the Hoa Lo prison camp, tortured by his captors after refusing to be released ahead of his less-famous jail mates.
After his release in 1973, McCain resumed his military career, eventually working as Navy liaison with the U.S. Senate. He moved to Arizona with his second wife in 1981 and, when GOP Rep. John J. Rhodes decided to give up his seat, McCain won the nomination to succeed him.
McCain eventually won retiring Sen. Barry Goldwater's seat in 1986. He quickly earned a reputation as a fiscal conservative and one who was unafraid to challenge President Ronald Reagan on foreign policy - an ``equal-opportunity critic'' as one colleague called him.
His quick rise was suddenly halted by the so-called Keating Five savings-and-loan scandal, in which McCain and four other senators were alleged to have interceded with bank regulators on behalf of financier Charles H. Keating Jr.
A lengthy ethics investigation ended in early 1991 with a mild rebuke for McCain, saying he had exercised poor judgment. Even so, he easily won reelection in 1992.
In 1994, his life was rocked again when it was revealed that his wife, Cindy, who had become addicted to painkillers during the early days of the Keating scandal, had been siphoning off prescription drugs from a medical assistance team she had set up in 1989 to work in developing countries. She narrowly escaped criminal indictment.
McCain's personal travails have not dimmed his aggressiveness in the Senate, where he has sometimes embarrassed GOP colleagues by identifying their patronage of pork. His volcanic temper and a strident manner are considered weak points, but most political observers praise his earnestness.
``He has a zealous commitment to politics that I've rarely seen in 30 years as a political consultant,'' said Bruce Merrill, who now teaches at Arizona State University. ``He is absolutely driven.''
Whether he is driven to a shot at the White House is an open issue. ``I don't know what his aspirations are; I'm not sure he does,'' said Michael Hellon, a GOP national committeeman from Arizona.
Although McCain spent the early stages of the presidential campaign as national chairman of the candidacy of Texas Sen. Phil Gramm, he signed on as senior adviser to Dole soon after Gramm dropped out, something not every politician could get away with.
Dole and McCain had grown close since last December's debate on committing U.S. troops to Bosnia. At that time, Dole revealed on the Senate floor that in the early 1970s he had worn a POW-MIA bracelet bearing the name of someone who was now a colleague - McCain.
The younger man had been unaware of this. In his nominating speech for Dole at the GOP convention, McCain said: ``A long time ago, in another walk of life, I was deprived of my liberty,'' and went on to publicly thank a fellow hero from another war.
``One of the more moving moments of an otherwise pedestrian convention,'' GOP consultant Doug Bailey said later.
This week, McCain said that he was still ``a little sad'' about Dole's defeat, although he admitted he saw it coming ``a long time ago.''
``One side of me, the practical side, said he probably can't win it,'' McCain said softly. ``You sort of accept that. And you soldier on.''