(a) A political party’s state, district, county, or precinct executive committee, as appropriate for the particular office, may nominate a candidate for the unexpired term if:
(1) in the case of a party holding a primary election, the vacancy occurs after the fifth day before the date of the regular deadline for candidates to file applications for a place on the ballot for the general primary election; or
(2) in the case of a party nominating by convention, the vacancy occurs after the fourth day before the date the convention having the power to make a nomination for the office convenes.
(b) The nominating procedure for an unexpired term under this section is the same as that provided by Subchapter B, Chapter 145, for filling a vacancy in a party’s nomination, to the extent that it can be made applicable.