Cal. Elec. Code § 7409

In the event that the candidates elected to a committee from a district do not equal the number of party committeemembers to which that district is entitled to be represented, a vacancy or vacancies exist to the extent of the difference between the number of elected committeemembers and the number of committeemembers by which the district is entitled to be represented. When a vacancy or vacancies exist they shall be filled by the committee to which insufficient members were elected, in the manner provided for in Section 7410.