Arizona is one of seven states which does not have a lieutenant governor; instead, in the event of a vacancy in the office of governor, the Secretary of State, if elected, succeeds to the office. If the secretary of state was appointed, rather than elected, or is otherwise ineligible to hold the office of governor, the first elected and eligible person in the line of succession assumes the office. The state constitution specifies the line of succession to be the Secretary of State, Attorney General, State Treasurer and Superintendent of Public Instruction, in that order. If the governor is out of the state or impeached, the next elected officer in the line of succession becomes acting governor until the governor returns or is cleared. To date, the line of succession has gone beyond the secretary of state only once, when Bruce Babbitt, as attorney general, became governor upon the death of Wesley Bolin; Rose Mofford, then serving as secretary of state, had been appointed to replace Bolin after Bolin succeeded to the governorship. Bolin had become governor when Raúl Héctor Castro resigned to accept appointment as U.S. Ambassador to Argentina. Mofford later became acting governor after Evan Mecham was impeached by the House of Representatives, and succeeded to the governorship when Mecham was removed from office after his conviction by the Senate.