John McCain's selection of Sarah Palin for vice president is easily the biggest and smartest strategy shift of any campaign in the last 18 months.

Realizing that a campaign on experience alone could not win (it certainly didn't work for Hillary), McCain smartly changed the focus to what that experience looks like: regular rhetoric versus a record of reform.

Cynics in the Obama camp will try to say Palin's only qualification is her gender, but Palin's time in office shows that she's a reformer just like McCain. By choosing the Alaska governor, McCain has made this critical character trait the cornerstone of his candidacy, and neither Obama nor Biden has the ability to compete on this.

One of McCain's best and most underplayed attributes this campaign season has been his willingness to depart from party orthodoxy on the basis of principle. He's bucked Bush on torture, led the mob against Jack Abramoff, worked with Ted Kennedy on immigration, co-authored campaign finance reform with Russ Feingold, and advocated action against climate change in a party which pretends the environment is inconsequential. In a party which can spend as flagrantly and wastefully as the Democrats, McCain has challenged earmarks, investigated dubious pricetags, and promoted greater fiscal responsibility.

In Alaska, Palin has shown similar courage. As chairwoman of an Alaskan energy commission, Palin investigated ethical improprieties by a fellow Republican committee member and state party chairman. In 2006, she took on the Republican governor as an outsider and won. She has shown a willingness to fight the party establishment and weed out corruption.

The McCain-Palin ticket has completely altered the race, because it puts Obama up against a charge he hasn't faced before. That is, for all his lofty rhetoric of a new politics, Obama has not exhibited the courage of standing up to his own party. He picks party regulars like Joe Biden for his White House and breaks promises on public financing for the general election.

A bold, unconventional McCain has rescued himself from a powerful but ultimately inadequate argument of experience.

The new argument he's added, a record of reform, was always there. It's a winning message.