New York Times reporter Jodi Kantor, in a book to be published Tuesday, portrays a White House where tensions developed between Mrs. Obama and former White House Chief of Staff Rahm Emanuel and former press secretary and presidential adviser Robert Gibbs. Among the book's most provocative anecdotes, Kantor recounts a scene in which Gibbs, frustrated after tamping down a potential public relations crisis involving the first lady, exploded when presidential adviser Valerie Jarrett told him the first lady had concerns about the White House response to the flap. The initial commotion had been over an alleged remark by Michelle Obama...