This appears to be the relevant statute in California (bold emphasis added by yours truly):
ELECTIONS CODE SECTION 8800-8811
8800. No candidate whose declaration of candidacy has been filed for any primary election may withdraw as a candidate at that primary election.
8801. No candidate nominated at any primary election may withdraw as a candidate at the ensuing general election except those candidates permitted to withdraw by this part.
8802. Any person nominated by a party at the direct primary election for a partisan office may be appointed to fill a vacancy on the general election ballot for any other partisan office, as provided in Section 8806, and in that case his or her appointment shall constitute a vacancy on the general election ballot for the office for which he or she was nominated. The vacancy thus arising shall be filled in the manner prescribed in Section 8806.
8803. No vacancy on the ballot for a general election shall be filled except if the candidate dies and that fact has been ascertained by the officer charged with the duty of printing the ballots at least 68 days before the date of the next ensuing general election.
8804. Notwithstanding Sections 8803 and 8810, any candidate who has been nominated at any primary election for superior court judge in which election there were at least two other candidates and who, after the date prescribed for the filing of declaration of candidacy pursuant to Article 2 (commencing with Section 8020) of Chapter 1 of Part 1, has been appointed to any federal or state office, may request the county elections official to have his or her name removed from the ballot of the next ensuing general election. If the request is received by the county elections official at least 68 days before the next ensuing general election, the county elections official shall remove the candidate's name from the ballot. If a candidate's name is removed from the ballot pursuant to this section, the two remaining candidates who received the highest number of votes cast on all the ballots of all the voters participating in the primary election for nomination for that office of superior court judge shall be the candidates for that office at the ensuing general election, and their names as candidates for that office shall be placed on the official ballot at the ensuing election.
8805. Whenever a candidate for nomination for a partisan office at a primary election dies on or before the day of the election, and a sufficient number of ballots are marked as being voted for him or her to entitle him or her to nomination if he or she had lived until after the election, a vacancy exists on the general election ballot, which shall be filled in the manner provided in Section 8806 for filling a vacancy caused by the death of a candidate.
8806. Vacancies permitted to be filled may, in the case of legislative offices, be filled by the county central committee or committees of the party in which the vacancy occurs, in the county or counties comprising the legislative district of the deceased candidate. In the case of all other district or state offices requiring party nomination, except congressional offices, the vacancies may be filled by the state central committee of the party.
Vacancies permitted to be filled may, in the case of congressional offices, be filled by those members of the state central committee of the party who reside in the congressional district in which the vacancy occurs, and who were registered to vote in that district at the time the vacancy occurred, acting together with the members of the county central committee or committees of the party residing in that congressional district. References in this section to state and county central committees shall be construed to refer to the newly elected or selected state and county central committees, unless the organizational meetings of those committees are held in January following the general election.
8807. If the vacancy occurs among candidates chosen at the direct primary to go on the ballot for the succeeding general election for a nonpartisan office, the name of that candidate receiving at the primary election the next highest number of votes shall go upon the ballot to fill the vacancy.
8808. A vacancy authorized to be filled because of the death of a candidate shall be filled, and the name of the person named to fill the vacancy shall be certified to the officer charged with the duty of printing the ballots, 68 days before the day of election.
8809. Whenever a candidate has declared a candidacy for a primary election, the candidate's name shall be printed upon the ballot for the primary election, unless the candidate has died, and that fact has been ascertained by the officer charged with the duty of printing the ballots, at least 68 days before the day of the election.
8810. Whenever a candidate has been nominated at any primary election after having filed a declaration of candidacy, the name of the candidate shall be printed upon the ballot for the ensuing general election unless the candidate has died and that fact has been ascertained by the officer charged with the duty of printing the ballots, at least 68 days before the day of election.
8811. Whenever, upon the death of any candidate, the vacancy created is filled by a party committee, a certificate to that effect shall be filed with the officer with whom a declaration of candidacy for that office may be filed, and, upon payment of the filing fee applicable to the office, shall be accepted and acted upon by that officer as in the case of an original declaration certificate.
I just read that all over again, and unless I'm missing something important, or unless Gallegly is planning to die by August, the GOP might wanna start gearing up for a write-in campaign..