Abbott’s order shuttered dozens of mail ballot drop-off sites. He issued the order Oct. 1, after voters had started returning ballots.
Democrats and voting rights groups accused the Republican governor of voter suppression, arguing the order most directly affected the state’s largest cities, which are Democratic strongholds. The League of United Latin American Citizens filed suit earlier this month.
Abbott said the move was designed to "strengthen voting safety in Texas."
Judge Robert Pitman said the directive imposed a "burden on an already vulnerable voting population that is somewhere between 'slight' and 'severe.'"
“The public interest is not served by Texas’ continued enforcement of a proclamation plaintiffs have shown likely violates their fundamental right to vote. This factor therefore weighs in favor of a preliminary injunction,” Pitman wrote in his opinion.
Harris County, where Houston is located, has a population of 5 million and is 1,777 square miles. Before the directive, it had 11 ballot drop sites. In a previous filing, the Harris County clerk warned that the lone drop off site "could be more than fifty miles away" for some voters.
Republicans said drop-off sites needed to be reduced to ensure election security – Abbott emphasized that his directive would allow poll watchers to oversee ballot deliveries. President Trump has urged supporters to go to polling places and “watch very carefully.”
Texas is one of five states not allowing widespread mail-in voting amid the coronavirus pandemic. In order to be eligible for mail voting, Texas residents must be 65 or older, disabled, out of the county on Election Day and the early voting period or in jail but otherwise eligible.
Despite Democratic attempts to expand mail voting in the state, courts have sided with GOP lawmakers.
In July, Abbott extended the state’s early voting period by six days to help Texans vote in a way that "mitigates the spread of the virus. Early voting begins Oct. 13.
The deadline to request a ballot in Texas is Oct. 23 and mail-in ballots must be postmarked by Nov. 3 and received by 5 p.m. Nov. 4.
The Associated Press contributed to this report.