 Hours away. I'm Lisa Lucera, Fox News. President Biden and former President Trump are in Atlanta ahead of the CNN presidential debate, their first square off of this election cycle. This is a big night, but there are a lot of unknowns. Will the two men shake hands on stage when they first are called out? We don't know that. How will the new rules play out? There's no live audience and the mics will be cut unless it's that particular candidate's turn to speak.