Mr. Presidential Democratic Nominee Obama, fasten your seat bet. We're talking a bumpy ride. Scorched earth policy. Swift Boat time, The GOP's first salvo is a book. Already written by National Review's David Freddoso, whose playpen is politics. . . . Publisher, Regnery. Ships to stores, July. On shelves, August. Price $37.95. Title, the longest in captivity: "Scorcher. The Case Against Barack Obama: The Unlikely Rise and Unexamined Agenda of the Media's Favorite Candidate." The so-called scorching? . . .