Analyst: Republican U.S. Senate candidate Kathy Barnette is surging in the polls because top contenders David McCormick and Mehmet Oz spent months tearing each other down in negative campaign ads. (May 13) Subscribe for more Breaking News: http://smarturl.it/AssociatedPress Website: https://apnews.com Twitter: https://twitter.com/AP Facebook: https://facebook.com/APNews Instagram: https://www.instagram.com/APNews/ ​ You can license this story through AP Archive: http://www.aparchive.com/metadata/youtube/bbbc7f9d3cf0408abaf373b227d8db61