Texas Constitution art. 16 §40

(a) No person shall hold or exercise at the same time, more than one civil office of emolument, except that of Justice of the Peace, County Commissioner, Notary Public and Postmaster, Officer of the National Guard, the National Guard Reserve, and the Officers Reserve Corps of the United States and enlisted men of the National Guard, the National Guard Reserve, and the Organized Reserves of the United States, and retired officers of the United States Army, Air Force, Navy, Marine Corps, and Coast Guard, and retired warrant officers, and retired enlisted men of the United States Army, Air Force, Navy, Marine Corps, and Coast Guard, and officers and enlisted members of the Texas State Guard and any other active militia or military force organized under state law, and the officers and directors of soil and water conservation districts, unless otherwise specially provided herein. Provided, that nothing in this Constitution shall be construed to prohibit an officer or enlisted man of the National Guard, the National Guard Reserve, the Texas State Guard, and any other active militia or military force organized under state law, or an officer in the Officers Reserve Corps of the United States, or an enlisted man in the Organized Reserves of the United States, or retired officers of the United States Army, Air Force, Navy, Marine Corps, and Coast Guard, and retired warrant officers, and retired enlisted men of the United States Army, Air Force, Navy, Marine Corps, and Coast Guard, and officers of the State soil and water conservation districts, from holding at the same time any other office or position of honor, trust or profit, under this State or the United States, or from voting at any election, general, special or primary in this State when otherwise qualified. (b) State employees or other individuals who receive all or part of their compensation either directly or indirectly from funds of the State of Texas and who are not State officers, shall not be barred from serving as members of the governing bodies of school districts, cities, towns, or other local governmental districts. Such State employees or other individuals may not receive a salary for serving as members of such governing bodies, except that: (1) a schoolteacher, retired schoolteacher, or retired school administrator may receive compensation for serving as a member of a governing body of a school district, city, town, or local governmental district, including a water district created under Section 59 , Article XVI, or Section 52 , Article III; and (2) a faculty member or retired faculty member of a public institution of higher education may receive compensation for serving as a member of a governing body of a water district created under Section 59 of this article or under Section 52 , Article III, of this constitution. (c) It is further provided that a nonelective State officer may hold other nonelective offices under the State or the United States, if the other office is of benefit to the State of Texas or is required by the State or Federal law, and there is no conflict with the original office for which he receives salary or compensation. (d) No member of the Legislature of this State may hold any other office or position of profit under this State, or the United States, except as a notary public if qualified by law. (Feb. 15, 1876. Amended Nov. 2, 1926, Nov. 8, 1932, Nov. 7, 1972, Nov. 6, 2001, and Sept. 13, 2003; Subsec. (a) amended Nov. 3, 2009.)