Impeachment witness Charles Kupperman distanced himself from acting White House chief of staff Mick Mulvaney on Monday as Mulvaney attempted to join Kupperman's lawsuit testing House subpoena power.
A federal judge will consider a lawsuit over a key White House official's House subpoena in mid-December, meaning some key impeachment witnesses like former national security adviser John Bolton may be beyond the reach of Democrats as they try to rapidly pursue their investigation of the President.
A former Reagan administration official and defense executive has been tapped to serve as deputy national security adviser.
