The presiding officer of the appropriate legislative chamber shall fill any vacancies occurring on the committee by appointment from the same political party as the departing member. Notwithstanding the provisions of RCW
44.39.015 as now or hereafter amended, any such appointee shall be deemed installed as a member upon appointment. Members filling vacancies shall serve until they or their successors are installed as provided in RCW
44.39.015, as now or hereafter amended, or until they are no longer members of the legislature, whichever is sooner.