Four senior White House officials refused to testify Monday in the House impeachment investigation despite being served with subpoenas. The officials include the White House’s top national security lawyer John Eisenberg, National Security Council lawyer Michael Ellis, national security aide Robert Blair, and budget official Brian McCormack. The witnesses cited orders from the White House and an opinion from the Justice Department’s Office of Legal Counsel—but refused to give that opinion to Democrats, despite their demand for it. Some Democrats have signaled that the closed-door testimony given by senior national security and State Department officials thus far is more than enough to move forward into the public phase of impeachment. Acting Ambassador to Ukraine William Taylor reportedly testified that U.S. military aid to Ukraine was made on the promise that investigations into the Bidens would be announced. And National Security Council official Alexander Vindman reportedly testified that the Ukraine call memo omitted key words and phrases. It is unclear if Democrats will further pursue the absent officials’ testimony, a process that could take months to procure via the courts.