GOP presidential candidates Mitt Romney and Ron Paul on Thursday had backed out of the planned March 1 debate in Atlanta, and Rick Santorum had not responded. So CNN went ahead and canceled the event this afternoon, saying its debate in Arizona on February 22 moderated by John King will go ahead as planned. The Romney and Paul camps ciited conflicts with campaign schedules ahead of the eight-primary Super Tuesday on March 6 as reasons for not attending; only Newt Gingrich among the four remaining candidates had agreed to show up. It would have been the 19th televised debate this presidential election cycle among the broadcast and cable news networks.