The Butler, Pennsylvania rally assassination attempt on Donald Trump Saturday has — for now — taken attention away from Democratic officials’ calls for President Joe Biden to step aside following his poor debate performance last month. When those calls inevitably pick back up, Michigan Advance editor-in-chief and columnist Susan J. Demas submits in a Sunday op-ed that she knows exactly what it would likely take for Biden to move on. Despite “the dump Biden furor appeared to hit a fever pitch post-debate,” Demas notes that she has since “looked for three factors to assess if the president will …