St. Paul City Council Member Dai Thao is challenging a Minnesota law that prohibits candidates for office from helping voters cast ballots, about a year after a judge found that Thao acted legally when he helped a woman vote while running for mayor.

A lawsuit filed Tuesday in Ramsey County court names Minnesota Secretary of State Steve Simon in his official capacity, and alleges that state statute violates the Voting Rights Act and both the state and federal constitutions by making it a criminal offense for candidates to assist voters or for individuals to assist more than three voters.

Plaintiffs include Thao; his wife, Amee Xiong; Council Member Nelsie Yang; and community organizer Chong Lee.

“The plaintiffs are all Hmong-Americans that have either needed assistance in voting and/or provided assistance to other eligible voters in Minnesota,” the complaint says. “They are representative of Minnesotans throughout the state struggling to make the voices of their communities heard by voting.”

The complaint notes Thao’s criminal case as “a clear example of this struggle.” Thao was charged in February 2018 with three misdemeanor counts of unlawfully marking a ballot, misconduct in and near polling places and unlawfully assisting a voter, after helping a woman vote in 2017 when he was running for mayor.

Ramsey County District Court Judge Nicole Starr issued an order in Thao’s case in October 2018 finding the Voting Rights Act pre-empts state law, and issued a decision the next month stating that Thao was not guilty of any of the criminal charges filed against him.

“This case builds on the ruling we obtained in that criminal case, which found the statute to violate the Voting Rights Act,” said Joe Dixon, who represented Thao in the criminal case and is one of the attorneys representing the plaintiffs in the suit against Simon.

In an interview, Thao said he started looking for partners to help change the state law while his case was pending, and ended up joining with ACLU Minnesota. The complaint lists six attorneys, including two from the ACLU.

“I just felt like something needed to happen,” Thao said. “It’s just uplifting that we can take that incident and turn it into something positive to change this law that will benefit everybody in the entire state.”

In an e-mail, a spokeswoman for Simon said the Secretary of State’s Office does not comment on pending litigation.

At a state House committee hearing in January 2019, Simon testified in support of a bill that would eliminate the legal limit on the number of voters one person can assist. Only one other state — Arkansas — has such a limit, Simon said.

“If we don’t repeal this law, it may be repealed, in effect, for us, at considerable expense,” he said, adding that his office was contacted in 2017 about a potential lawsuit related to the law, and that a federal court recently struck down a similar law in Texas.

“I guess the bottom line is this, if I had to be just blunt about it: I think we can do this the easy way, or we can do it the hard way,” he said.