The term of office of judges of the Supreme Court shall be eight (8) years. Concurrently with the regular election for representatives in Congress, held next preceding the expiration of the term of an incumbent, and likewise each eighth year thereafter, an election shall be held in the Supreme Court district from which such incumbent was elected at which there shall be elected a successor to the incumbent, whose term of office shall thereafter begin on the first Monday of January of the year in which the term of the incumbent he succeeds expires.