text:  From ABC News, I'm Lindsay Davis, anchor of Prime, streaming weeknights on ABC News Live. The historic debate between President Biden and former President Trump now just hours away. It will be the first time a sitting president debates a former one. More now from ABC's Rachel Scott. So much has changed since the last time these two candidates saw each other. January 6th, the pandemic. We know the former president is preparing to take questions on that as well as his legal troubles. President Biden preparing to take questions on everything from his age to issues like immigration.