In a sign of the state’s flirtation with battleground status, Texas is being hit with a third voting rights lawsuit filed by national and Texas Democrats — this time targeting the state’s voter registration requirements.

In a federal lawsuit filed Monday in San Antonio, the Texas Democratic Party and the campaign arms for Democrats in the U.S. House and Senate allege that Texas is violating the U.S. Constitution and federal and state law by rejecting voter registration applications with electronic signatures.

The legal challenge springs from a 2018 electoral kerfuffle over the Texas secretary of state’s rejection of more than 2,400 registration applications filled out by voters using Vote.org, a website run by a California nonprofit. That online application asked Texans to provide personal information and a picture of their signature to auto-populate a paper voter registration form that was then mailed to county registrars.

Days before a registration deadline that year, the secretary of state’s office indicated that applications submitted through the website should be considered invalid because they included electronic signatures, not physical ones.

In the lawsuit, the Democrats argue the secretary of state’s signature requirements are unconstitutional and impose “an arbitrary requirement that limits access to the franchise.” While the state allows eligible Texans to submit registration applications in person, by mail or by fax, Texas law “makes no reference” to requiring an original signature, they argue in the legal challenge.

Citing violations of the First and 14th Amendments and the federal Civil Rights Act, the state and national Democrats want a federal judge to block the state from enforcing the original signature rule and keep county registrars from rejecting voter registration applications.

“This unconstitutional ban does not make an ounce of sense, and it is the kind of arbitrary voter suppression that we’re working to tear down right now before even more harm is done to our Democracy,” U.S. Rep. Cheri Bustos of Illinois, who chairs the Democratic Congressional Campaign Committee, said in a statement.