(1) In the year 1956, and each fourth year after 1956, delegates of each political party who were elected to the last prior fall county convention shall reconvene in a county convention. The county conventions, when so convened, shall elect delegates to a state convention. The number of delegates elected shall be the same as the number elected to the last prior spring state convention. The county conventions shall be held at least 90 days prior to the time set for the holding of the national convention of its political party. All county conventions shall be held on the same day and time. The time and place shall be fixed by the state central committee. A state convention composed of delegates elected by the respective county conventions shall be held in the year 1956, and each fourth year after 1956, at least 60 days before the holding of the national convention of its political party.

    (2) As used in this section:

    (a) “Delegates of each political party who were elected to the last prior fall county convention” means precinct delegates elected at the last prior August primary election, persons nominated as candidates for county offices and state legislative offices who are delegates at large to county conventions under section 599(5), and delegates elected under section 622 or 624d to fill a precinct delegate vacancy for the balance of an unexpired term.

    (b) “Persons nominated as candidates for county offices and state legislative offices who are delegates at large to county conventions under section 599(5)” means incumbent county officials, incumbent state legislators, and unsuccessful candidates for county offices and state legislative offices who are candidates at the last prior regular or special election held for the respective office.

    (3) Delegates to a state convention shall include only those delegates elected at a county convention.