Desiree Rogers, the White House social secretary, is resigning her position just a few months after she was roundly criticized for a security lapse that led to uninvited guests crashing the president's first state dinner. "It's been a tremendous experience and honor to serve this president and first lady in what is really a historic presidency for all Americans but particularly for African-Americans," she said in a brief telephone interview. "That is part of the reason I came out to do the job." Ms. Rogers was a newcomer to politics as well as to Washington, and in her first year...