The two remaining Democratic candidates for president will meet in their sixth debate and second one-on-one contest. The PBS Newshour debate, to be held in Milwaukee, Wisconsin, will surely re-address old issues and may bring new ones to the fore. Pundits will be looking for signs that Sanders is positioning himself as a president rather than the leader of a movement. And they push for more information about his background. Also, of significant interest, is whether Hillary Clinton will come out swinging as she did in the most recent debate.