With ballots now in the hands of some Denver voters, 11 leading mayoral candidates gathered at a school in northeast Denver on Tuesday for a televised debate that was noticeably nastier than previous gatherings as the cluster of people in the race sought to create separation. Lisa Calderón, Mike Johnston, Kelly Brough, Chris Hansen, Debbie Ortega, Leslie Herod, Al Gardner, Thomas Wolf, Trinidad Rodriguez, Terrance Roberts and Andy Rougeot were the 11 of the 17 people running for mayor in the April 4 election invited to Tuesday’s showdown, hosted by 9News and aired on sister station KTVD. That roster was decided via polling commissioned by 9News, Colorado Politics, the Denver Gazette and Metro State Univeristy at the end of February.