Bill Clinton's poll ratings are in free-fall, and that surprise crash undermines the conventional wisdom that Hillary Clinton has a lock on the Democrat nomination. A new CBS/New York Times poll shows that just 39 percent of American voters have a favorable opinion of Bill Clinton. This is down from a 50 percent approval rating just a few months ago. In 2012...66 percent of voters had a favorable opinion of Mr. Clinton. Bill Clinton's favorable rating today is actually lower than it was in 2008, when he last campaigned forcefully for Hillary as she was battling Barack Obama for the...