Sometimes, as we all know, it's better to be lucky than good. The most compelling, contemporary case in point: Sen. John McCain.
He wanted his buddy, Sen. Joseph I. Lieberman, to be his running mate. Wasn't happening. The former Democrat from Connecticut is pro-abortion rights. A conservative, right-to-life GOP, already shaky, might have disintegrated.
Enter Sarah Palin, the 44-year-old governor of Alaska, who initially prompted a reaction reminiscent of the famous cry, four decades ago, of "Spiro who?" Spiro T. Agnew, the Maryland governor, was only slightly better-known in 1968 than Mrs. Palin was a week ago. Mr. Agnew and Richard M. Nixon won - and much of the credit was given to Mr. Agnew.
He had moved from a Baltimore County PTA leader to the vice presidency of the United States in six years, light-speed compared with the time it often takes to move up the ladder of politics.
Who knows if Governor Palin's progress will be as meteoric? She may not have the same penchant for alliteration that colored the language of Mr. Agnew. But she does have some of the same appetite for the rapier thrust. She's a practiced public presenter and, it seems, as committed a warrior for her party as Mr. Agnew.
One comparison is to be avoided: The GOP certainly hopes that Mrs. Palin will not fall victim to the ethical pitfalls succumbed to by Mr. Agnew, who pleaded no contest to charges of corruption in office. No one can say whether a longer ascent to power might have supplied a sense of right and wrong.
Unlike Mrs. Palin, Mr. Agnew had shown no propensity for reform. He became prominent as an opponent of what he may have honestly seen as untoward progress in civil rights. He was, in a sense, the embodiment of his party's Southern strategy.
In choosing Mrs. Palin, Mr. McCain and his strategists had far different objectives. Outside the world of politics, though, she was greeted at first with something like the reception accorded Mr. Agnew. Few really knew her outside Alaska.
Surely they hoped images of her large family might slow the momentum of Sen. Barack Obama, whose charisma and personal story have given the Democrat a boost in the polls. And as much as they love to hate "the media," they wanted to take back Page One.
As a guided political missile, she was instantly effective - crisp and combative. Leaping, as if full-blown from the brow of campaign strategists, she knocked the Democratic nominee to the inside pages. Mr. McCain, as one commentator observed, became second banana at his own convention; his acceptance speech Thursday night was received less enthusiastically than her Wednesday evening address.
Mrs. Palin showed the world why her nickname is Sarah Barracuda. She might be the perfect No. 2, a woman quite capable of taking the fight to her opposite number, Sen. Joe Biden of Delaware
She faces more tests, of course. She spoke of issues only in the most general way. She seemed more the street fighter than the person who could take over the White House. Her job, though, was to complement Mr. McCain, and that she seemed to accomplish.
She was the candidate as Superwoman, able to fly through the vaunted glass ceiling; a nurturing, moose-hunting NRA member; a beauty queen; a really swell point guard; the scourge of big oil; and a reformer - of her own party.
And to think, it might have been Joe Lieberman.
C. Fraser Smith is senior news analyst for WYPR-FM. His column runs on Sunday. His e-mail is firstname.lastname@example.org.