Senators John McCain and Hillary Clinton would each have us believe that their years of experience in national politics and government will make them a far better president than their colleague Barack Obama, who has served just half a term in the United States Senate. McCain and Clinton are following a time-tested political strategy: to question an opponent's experience is to sow doubt about his competence and ability to govern, which makes people nervous about voting for him.

But if experience mattered most in life, Babe Ruth would have been a winning baseball manager, Dick Cheney would be considered a visionary, IBM would have led the personal computer revolution, and both Richard Nixon and Herbert Hoover would be judged among our greatest presidents whereas Abraham Lincoln and Woodrow Wilson would be among the worst.

So if history tells us that experience sometimes matters, sometimes doesn't, how else can we compare the competence and ability of our leading presidential candidates?

The best gauge may be to examine the one experience in which all three of them started from the same place: running for president. And on that account, the one with the least experience has hands down done the best.

From money to message to campaign organizing to drawing voters, Obama has outpaced his two rivals and in fact has pioneered a number of new strategies that future candidates will dissect and study in the years ahead. His campaign has become the Apple or Google of American politics.

Consider campaign finances. Both Senators McCain and Clinton amassed considerable war chests last year as their party’s frontrunners – and both of them squandered their millions. McCain’s campaign bottomed out last summer, so much so that he had to fire key staff and take out a $4 million line of credit. Clinton spent so carelessly in the early contests this winter – $11,000 for pizza and $1,200 for Dunkin' Donuts in January alone – that she had little left to compete after Super Tuesday and was forced to loan her campaign $5 million.

Obama started out behind in the money primary, but rather than pour all of his resources into early advertising, grand gestures, and top-heavy consultants, he did as any savvy business would do – invest in future growth, which in his case meant opening offices and hiring staff in the caucus states, starting with Iowa, which turned out to be critical in his string of electoral successes.

He also nurtured hundreds of thousands of donors, many on-line, who gave a little at first and then a little more and then even more, which constantly nourished his campaign. Clinton and McCain focused on the big donors, many of whom maxed out and couldn't contribute more when the campaigns needed it.

Obama also cultivated grass-roots support far better than his opponents. For volunteers, he began a series of regional training camps in the spring of 2007, teaching outreach, door-to-door targeting and phone bank techniques, essentially bringing these volunteers up to the level of professional organizers. His mobile phone and on-line viral technology, according to Wired magazine, "has been one of the most effective in its embrace of new tech strategies."

Obama showed himself a shrewd student of political history, learning perhaps the most important lesson from President Bush's successful reelection campaign. While McCain and Clinton sought to secure support from their respective party's establishment, which at first blush seemed like a smart move, Obama instead understood that the mobilization of evangelical shock troops that helped Bush succeed in 2004 could be replicated through the ardor of an Obama volunteer army that would serve as precinct captains and local volunteers who knew their communities and how to bring out voters.

Those who deride Obama for running a campaign of religious fervor miss the point: it's this passionate faith in Obama that has enabled him to organize on the ground in the same way Bush's religious supporters gave him an edge in 2004.

Finally, Obama never wavered in his message – he has always vowed to get things done for America by changing the way Washington works. McCain ran his 2000 campaign with a similar outsider message, and has returned to it again, but in between he pandered to religious right leaders he once called "agents of intolerance," backtracked on his opposition to the Bush tax cuts, and until finding his inner hawk he seemed unable to explain his rationale for becoming president. As for Clinton, her initial message spoke to her inevitability as if she were the incumbent waiting to be anointed, but after losing Iowa, she began listing from one feckless slogan to another, not unlike her failed attempt to sell healthcare reform in 1993.

To be sure, both McCain and Clinton have demonstrated an admirable ability to get off the mat and revive their campaigns – Clinton winning New Hampshire after her drubbing in Iowa, and McCain, the real comeback kid of 2008, capturing the Republican nomination only months after the chattering class grimly declared that his candidacy was on life support.

But their resilience, impressive as it may be, is no better than the grit Obama showed after his campaign was written off as listless last year when he trailed Clinton by 30 percent in the polls and by millions in the money primary and seemed to have no chance of winning the nomination.

It may well be that the person who runs the best campaign won’t turn out to be the best president. But for voters who do their comparison shopping, it's instructive to see how each of these candidates – given their different life experiences – has met the exact same challenge.