 I'm Mark Remillard. The first presidential debate of the election cycle takes place tonight in what will mark the first time a sitting president debates a former one. The stakes are high and the polls are close. This will be the first time in four years that President Biden and former President Donald Trump will be in the same room. Two different debate preparations and strategies here. We know the president has been hunkered down at Camp David holding mock debates with his senior advisers.