Here’s a great New Yorker piece by Jane Mayer on how John McCain decided to pick Sarah Palin.
Upon being elected governor, Palin began developing relationships with Washington insiders, who later championed the idea of putting her on the 2008 ticket. “There’s some political opportunism on her part,” Bitney said. For years, “she’s had D.C. in mind.” He added, “She’s not interested in being on the junior-varsity team.”
During her gubernatorial campaign, Bitney said, he began predicting to Palin that she would make the short list of Republican Vice-Presidential prospects. “She had the biography, I told her, to be a contender,” he recalled. At first, Palin only laughed. But within a few months of being sworn in she and others in her circle noticed that a blogger named Adam Brickley had started a movement to draft her as Vice-President. Palin also learned that a number of prominent conservative pundits would soon be passing through Juneau, on cruises sponsored by right-leaning political magazines. She invited these insiders to the governor’s mansion, and even led some of them on a helicopter tour.