Maine constitution
Article IX: general provisions
Section 2

No person holding the office of Justice of the Supreme Judicial Court, or of any inferior court, Attorney General, district attorney, Treasurer of the State, Adjutant General, judge of probate, register of probate, register of deeds, sheriffs or their deputies, clerks of the judicial courts, shall be a member of the Legislature; and any person holding either of the foregoing offices, elected to, and accepting a seat in the Congress of the United States, shall thereby vacate said office; and no person shall be capable of holding or exercising at the same time within this State, more than one of the offices before mentioned.