Texas Constitution art. 16 §65

(a) This section applies to the following offices: District Clerks; County Clerks; County Judges; Judges of the County Courts at Law, County Criminal Courts, County Probate Courts and County Domestic Relations Courts; County Treasurers; Criminal District Attorneys; County Surveyors; County Commissioners; Justices of the Peace; Sheriffs; Assessors and Collectors of Taxes; District Attorneys; County Attorneys; Public Weighers; and Constables. (b) If any of the officers named herein shall announce their candidacy, or shall in fact become a candidate, in any General, Special or Primary Election, for any office of profit or trust under the laws of this State or the United States other than the office then held, at any time when the unexpired term of the office then held shall exceed one year and 30 days, such announcement or such candidacy shall constitute an automatic resignation of the office then held, and the vacancy thereby created shall be filled pursuant to law in the same manner as other vacancies for such office are filled. (Added Nov. 2, 1954; amended Nov. 4, 1958, and Nov. 2, 1999; Subsec. (a) amended Nov. 6, 2007; Subsec. (b) amended Nov. 8, 2011.) (TEMPORARY TRANSITION PROVISIONS for Sec. 65: See Appendix, Note 1.)