Call it empty seat syndrome. While Republican presidential front-runner Donald Trump continues to draw overflow crowds by the thousands this week, Democratic race leader Hillary Clinton and one-time GOP front-runner Jeb Bush have seen their recent crowds dwindle along with their poll numbers. Bush, the one-time GOP front-runner who was deposed by Trump over the summer, drew only about 100 people to a recreation center in Summerlin, N.V., outside Las Vegas. It was the former Florida governor's first appearance following Wednesday night's prime-time national GOP primary debate, which brought record-high ratings for CNN. Also on Thursday, Clinton received a standing...