SInce they obviously can't take turns, it's time to take control of their microphones. Put the debaters in separate studios with the moderator isolated in the control room. A referee controls the toggle switch, Trump/Biden. Give each candidate exactly 30 minutes to answer 10 questions, mute the opposing candidate as the other answers. Allow exactly 3 minutes for answer. Each candidate can either rant and rave or answer the questions. No more interruptions of either speaker.