WASHINGTON A blistering comedy “tribute” to President Bush by Comedy Central’s faux talk show host Stephen Colbert at the White House Correspondent Dinner Saturday night left George and Laura Bush unsmiling at its close. Earlier, the president had delivered his talk to the 2700 attendees, including many celebrities and top officials, with the help of a Bush impersonator. Colbert, who spoke in the guise of his talk show character, who ostensibly supports the president strongly, urged the Bush to ignore his low approval ratings, saying they were based on reality, “and reality has a well-known liberal bias.” He attacked those...