The Senate trial of President Trump on two articles of impeachment is ongoing. Annette Elizabeth Allen for NPR hide caption

Trump Impeachment Inquiry: On-Air Special Coverage
Fiona Hill (left), the National Security Council's former senior director for Europe and Russia, and David Holmes, an official from the American Embassy in Ukraine, are sworn in to testify before the House Intelligence Committee in the Longworth House Office Building on Capitol Hill on Thursday. Chip Somodevilla/Getty Images hide caption
Former State Department special envoy to Ukraine Kurt Volker and former National Security Council Senior Director for European and Russian Affairs Tim Morrison testified before the House Intelligence Committee on Tuesday during the third day of open hearings in the impeachment inquiry against President Trump. Chip Somodevilla/Getty Images hide caption
Special Report: Takeaways From Day 3 Of Testimony In The Public Impeachment Hearings
The former U.S. Ambassador to Ukraine, Marie Yovanovitch, testified in front of the House Intelligence Committee on Friday in the public phase of the impeachment inquiry. Andrew Harrer/Getty Images hide caption
Special Report: What You Need To Know From Marie Yovanovitch's Public Testimony
Former U.S. Ambassador to Ukraine Marie Yovanovitch testifies before the House Intelligence Committee on Capitol Hill on Friday. Drew Angerer/Getty Images hide caption
Former U.S. Ambassador To Ukraine Marie Yovanovitch's Public Testimony Part 1
Two witnesses seen as crucial to the case against President Trump in the impeachment inquiry testified Wednesday. Jim Lo Scalzo/2019 Getty Images hide caption