Politicians routinely welcome conventioneers to their cities and states. But Colorado Gov. Bill Owens and Colorado Springs Mayor Lionel Rivera broke with the routine when one group came to town. Was it pedophiles or neo-Nazis? No, it was a convention of the Atheist Alliance. Rivera admits this was the first time in his 11 months in office he has refused to offer a letter of welcome to a visiting group that requested it. He says the atheists shouldn't have scheduled their convention so close to Easter and Passover. "Just because an organization sends in a request to have a letter from the governor, that doesn't mean a governor has to endorse a particular organization," said a spokeswoman for Owens.