Under Article II Section 4 of the Constitution, “The President, Vice President, and all civil Officers of the United States shall be removed from Office on Impeachment for, and conviction of, Treason, Bribery, or other High Crimes and Misdemeanors.” The question of whether members of Congress are considered “civil Officers” has not been conclusively decided; Senator William Blount was impeached by the House in 1798 but the Senate voted to dismiss on the grounds of lack of jurisdiction and he was instead expelled. As of 2017, 5 members of the House and 15 members of the Senate have been expelled, most of whom were expelled in 1861-62 for joining the Confederate States of America.