Texas Government Code - GOV'T § 437.208. Organization Prohibited

(a) Except as provided by Subsection (b), a body of persons other than the regularly organized Texas military forces, the armed forces of the United States, or the active militia of another state may not associate as a military company or organization or parade in public with firearms in a municipality of the state.

(b) With the consent of the governor, students in an educational institution at which military science is a prescribed part of the course of instruction may drill and perform ceremonies with firearms in public. The governor may delegate the powers granted by this subsection to the adjutant general.