LIKE RATS FROM A SINKING SHIP. Michael Gerson, the exceptionally skilled speechwriter who put all them purdy werds in the President's mouth, is retiring. "It seemed like a good time." Gerson said. "Things are back on track a little. Some of the things I care about are on a good trajectory." Apparently, one of the things he cared about was not the Bush presidency, now languishing in the mid-30's.