The terms of office of members of the board of governors of the state bar who are elected from the various congressional districts shall not be affected by the creation of either new boundaries for congressional districts or additional districts. In such an event, each board member so elected may continue to serve in office for the balance of the term for which he or she was elected or appointed: PROVIDED, That the board member continues to reside within the boundaries of the congressional district as they existed at the time of his or her election or appointment. Vacancies which occur in a board member position during the balance of any such term shall be filled pursuant to RCW 2.48.030, as now or hereafter amended, by a successor who resides within the boundaries of the congressional district from which the member whose office was vacated was elected as they existed at the time of his or her election. At the election immediately preceding expiration of the term of office of each board member provided for in this section following the creation of either new boundaries for congressional districts or additional districts, and thereafter, a successor shall be elected from the congressional district which corresponds in number with the congressional district from which the incumbent was appointed or elected.