Senators are set to vote Friday on whether to call witnesses in the impeachment trial of President Trump. Republicans believe they have enough votes to block witnesses and acquit the president. For more, we're joined by NPR's Ayesha Rascoe. And, the United Kingdom officially leaves the European Union on Friday. But the U.K. Ambassador to the U.S. Michael Tatham says he's not feeling so "starry-eyed" about Brexit.