Marine Corps Sgt. Zach Richardson survived Iraq, but not Carson Middle School in Greensboro. When Richardson walked into the Greene County school last week, he expected to meet some of the sixth-graders who had written to him during his seven-month deployment. Instead, he was shown the door, coming under the scrutiny of a principal enforcing a policy that requires prior approval for visiting speakers. Principal Ulrica Corbett told teacher Matthew Lund, the Marine's host and former college roommate, to escort Richardson from the campus. On Wednesday, after the incident had gotten attention across the nation, the superintendent of Greene County...