White House counsel Don McGahn in September. Lawyers for McGahn appeared in federal court on Thursday in a dispute over whether he will have to sit for questions from House investigators conducting the impeachment inquiry into President Trump. Saul Loeb/AP hide caption
Timothy Morrison arrives for a deposition in the House impeachment inquiry on Thursday. Saul Loeb/AFP via Getty Images hide caption
President Trump delivers the State of the Union address in the chamber of the U.S. House of Representatives on Feb. 5. Chip Somodevilla/Getty Images hide caption
Speaker of the House Nancy Pelosi leaves her weekly press conference on Capitol Hill on Thursday as the House prepared to vote — then pass — a resolution formalizing its impeachment inquiry into President Trump. Saul Loeb/AFP via Getty Images hide caption
Rep. Adam Schiff (center) chairs the House Intelligence Committee, which would conduct any open hearings under the House impeachment inquiry, according to procedures specified in a resolution formalizing the process. Patrick Semansky/AP hide caption
Tim Morrison, a key aide on the White House's National Security Council, is expected to leave his post imminently. Sarah Silbiger/Reuters hide caption
Catherine Croft, a specialist on Ukraine with the State Department, is one of two witnesses meeting behind closed doors with impeachment investigators on Wednesday. Win McNamee/Getty Images hide caption
State Department employee Christopher Anderson is testifying behind closed doors on Capitol Hill on Wednesday about the Trump administration's policy on Ukraine. Win McNamee/Getty Images hide caption
The Department of State building is shown in April 2019 in Washington, D.C. Mark Wilson/Getty Images hide caption
House Speaker Nancy Pelosi holds a news conference at the Capitol. Chip Somodevilla/Getty Images hide caption
U.S. House Intelligence Committee Chairman Rep. Adam Schiff walks to the closed-door deposition of Lt. Col. Alexander Vindman on Capitol Hill on Tuesday. Mark Wilson/Getty Images hide caption
President Trump speaks at CIA headquarters in Langley, Va., on Jan. 21, 2017, his first full day in office. Mandel Ngan/AFP/Getty Images hide caption
The early morning light hits the U.S. Capitol Building on Oct. 17. Mark Wilson/Getty Images hide caption
House investigators are speaking with Ukraine expert Lt. Col. Alexander S. Vindman as part of their impeachment inquiry into President Trump on Tuesday. Patrick Semansky/AP hide caption
House Speaker Nancy Pelosi announced on Monday that the House will vote to formalize its impeachment inquiry into President Trump. Above, she speaks to reporters earlier this month. Chip Somodevilla/Getty Images hide caption