The first impeachment of a sitting cabinet member sets off a series of choreographed rituals that dates back to the impeachment of former President Andrew Johnson in 1868.
During his second impeachment trial, the former president argued that criminal prosecution was a more appropriate way to seek accountability since he had left office.
The first House hearing on impeaching the homeland security secretary featured Republicans accusing him of willfully failing to enforce immigration laws and an expert who testified there was no case.
A lawyer for the former president said he would be immune from prosecution for the murder of a political rival unless he was first impeached and convicted in Congress.