MICHAEL GERSON deserves extra pay, or something, for agreeing to spend half a day earlier this month discussing with journalists a subject of some controversy–“Religion, Rhetoric, and the Presidency.” If anyone was qualified for such a task, it was Gerson. He is President Bush’s chief speechwriter, knows the president’s mind better than anyone else in the White House (save perhaps Karl Rove) and–no small thing–shares the president’s faith.