Previously, House Democrats have subpoenaed acting OMB Director Russel Vought and Secretary of State Mike Pompeo.
"Of course it's not appropriate," former National Security Adviser H.R. McMaster said, chucking. "Does anybody think it is appropriate?"
It's not just openly critical Republicans like Sen. Mitt Romney who have drawn Trump's ire — he is also angry at those who haven't defended him.
Giuliani added to allegations that Trump pressured foreign officials to investigate his potential 2020 Democratic opponent for his own political gain.
House Democrats are zeroing in on Trump's inner circle as they pursue the impeachment inquiry after a bombshell whistleblower complaint.
A whistleblower complaint that an intelligence official filed against Trump cites multiple White House officials as being the source of the complaint.
President Donald Trump reportedly derailed a meeting with world leaders at the G7 on Saturday evening after he insisted on Russia's readmittance.