The Texas Democratic Party is suing to overturn a state law on ballots.
The measure in question says candidates who belong to the same party as the governor are listed first on general election ballots.
The lawsuit filed in an Austin federal court on Friday argues that the law gives an unfair advantage to Republicans, the party of Gov. Greg Abbott, in every contested race on the ballot.
The ballot order law was first passed in 1985, when Democrat Mark White was the governor of Texas, and the Democrats were in the majority in both the state House and Senate.