The Latest: Pre-debate, Biden studying Trump's past comments

Joe Biden says he’s begun preparing for presidential debates that begin later this month by studying President Donald Trump’s past comments.“I haven’t been doing mock debates very much but I’ve been just making sure that I understand all that he has said and hasn’t said,” the Democratic presidential candidate told reporters as he prepared to fly back to his home state of Delaware on Tuesday night, after an event marking the start of Hispanic Heritage Mon