Should answer your questions ... Judges have been removed before.
Congress has authority to impeach and remove justices. No one doubts this. Does Congress have authority to engage in fact-finding pursuant to its oversight powers that are implied in its impeachment authority? Evidently, NRO says no. I say that without said fact-finding power, the impeachment power is de facto null and void.
SENATE: On what charges has the House impeached this justice?
HOUSE: We can’t say for sure, since we don’t have subpoena authority over the judicial branch.