Texas constitution
Article 6: suffrage
Section 2a

(c) Notwithstanding any other provision of this Constitution, the Legislature may enact laws and provide for a method of registration, including the time for such registration, permitting absentee voting for electors for President and Vice President of the United States in this State by former residents of this State (1) who have removed to another state, and (2) who meet all qualifications, except residence requirements, for voting for electors for President and Vice President in this State at the time of the election, but the privileges of suffrage so granted shall be only for such period of time as would permit a former resident of this State to meet the residence requirements for voting in his new state of residence, and in no case for more than twenty-four (24) months.