John McCain's choice of Sarah Palin was the most inspired decision of his long race for the White House. The ads lampooning Barack Obama's messianic pretensions were skillful as well. But the Palin pick accomplished several goals at once.

It is, it must be acknowledged, a terrible year to be a Republican. A decidedly unpopular Republican president is finishing his second term. Republican party identification is at its lowest point in 16 years (27 percent, according to the Pew Research Center). All indicia of excitement -- money raising, turnout at political events, buzz -- strongly favor the Democrats. Further, the attractive, articulate, and charismatic Democratic nominee is an historic first -- the first African-American nominated by a major party.

Who would have believed, two weeks ago, that Republicans would march out of their convention more pumped than they have felt since Reagan?

The choice of Palin has recast the entire election. Until McCain chose his vice president, the election was shaping up to be about "change." Obama was playing the role of knight errant, and McCain was cast as the candidate of the status quo. Many a Democratic speaker in Denver invited the delegates to regard a prospective McCain presidency as "Bush's third term."

McCain declined to play his appointed part. Had he chosen any of the most often mentioned candidates for the second spot -- Romney, Pawlenty, Ridge -- it would have been impossible to escape the sense of "same old same old" that would have followed the ticket like stale cigar smoke. However much one might revere older white guys, and some of my best friends are OWGs, there is no escaping the fact that this was not the year for such a ticket.

Liberals have indignantly protested that McCain's choice of a woman was a "cynical" bid for disgruntled Hillary Clinton voters. But I don't think that's what this was about. In Palin, McCain found a reformer. He sees himself as a reformer and a clean government crusader. One might not always agree with his idea of reform (certainly campaign finance reform struck me as a blow to the First Amendment), but that he sees himself in that role is indisputable. In Sarah Palin, he found, as David Brooks shrewdly observed, a kindred spirit. Not just a soul mate but a gal with pizzazz and spirit! Who can resist a governor who comes into office on a promise to clean house and promptly sells the luxury jet her predecessor had bought on eBay? (She let the chauffeur and chef go, too.) Palin has confronted the corruption of her own party, just as McCain has done in Washington by challenging those among his colleagues he calls, not affectionately, "the appropriators." This throws down the gauntlet to Obama to cite a single instance when his mantra of change has been backed by actions. Has he ever crossed swords with those in his party? Ever denounced corruption among Democrats? His acceptance speech was a liberal wish list indistinguishable in content from those of Mondale, Dukakis, Clinton, and Kerry. Is this change?

McCain must also have calculated that Palin's expertise on energy would help highlight the one domestic issue that has emerged as a clear winner for Republicans. One looks forward eagerly to the day when he explains that Sarah Palin has convinced him to reverse his opposition to drilling in ANWR.

And McCain must also have sensed that a young, attractive woman from a western state would inject a dose of energy and enthusiasm into the race. On this, McCain may not have even guessed at how right he was (though one senses that Cindy McCain knew). Sarah Palin is political dynamite. She has transformed Republicans from flaccid to fired-up overnight. Just by being pro-life, small town, patriotic, and religious, she set the teeth of the media types on edge. By being all of that AND smart and articulate, and a budget hawk, she sent conservatives over the moon.

Together McCain and Palin have changed the game. They have seized the mantle of reform and dare the Democrats to show anything comparable. In this worst of all years for Republicans, it no longer seems fanciful to imagine that they can win.