Sunday, December 22, 2019: A Week for the History Books

President Trump became the third President of the United States to be impeached this week. The Senate trial is expected to start early next year, once congressional leaders break an impasse over whether to call witnesses before a final vote. Plus, with six weeks until the Iowa caucuses, how did the last Democratic debate of the year turn into a fight over wine caves? Today's Panel: Axios' Margaret Talev, Rachel Bade and Seung Min Kim of the Washington Post, and CNN's Maeve Reston.

To learn more about how CNN protects listener privacy, visit cnn.com/privacy