John Walker Lindh's lawyers and parents appealed to President Bush for the fourth time Tuesday to commute the Marin County man's 20-year prison sentence for aiding the Taliban in 2001, saying the nation has grown less fearful since then and that others convicted of similar charges have been treated more leniently. "John Lindh had no involvement whatsoever in terrorism or criminal activity," his mother, Marilyn Walker, said at a news conference.... "Others have received a lot less in the way of a sentence even when they were convicted of a lot more," the lawyer said. Bush has not responded to...