April 29 is Day 100 of the Obama administration. Look for lots of attention from the press, but none from the White House, where they don't want to shorten the president's landing strip or accept a three-month scorecard at a time of unprecedented challenges. If you buy the storied hundred-days construct, it means you're less special or fresh on Day 101. Two different top Obama staffers derided the marker yesterday as 'A HALLMARK HOLIDAY.'