In an effort to overhaul San Diego Unified School District elections with a November ballot measure, an advocacy group is threatening the San Diego City Council with legal action if it fails to place the matter before voters.

In a letter sent last week, Community Voices for Education President Bret Caslavka took aim at the school board’s election process, which he says violates the California Voting Rights Act and dilutes the voting power of minorities living within the district.

According to the letter, the problem lies with how board seats are filled.

There are currently five seats on the school board that represent smaller, sub-districts inside San Diego Unified. School trustees must live in the district they represent.

Similar to City Council elections, only voters who live in the sub-districts can vote for a representative in an initial election, but the top two candidates must then go on to compete in a second, city-wide election in November.

The result, Caslavka said, is an underrepresented student and parent population on the board.

State education data show the district’s student population is about 46 percent Hispanic or Latino, 23 percent white, 8 percent Asian and 8 percent black. The remaining population includes Filipino and American Indian students, or those who identify as two or more races.

“Since its inception the [board] has had a total of three Latino and one Asian trustee,” Caslavka said in the letter. “As a result of the abridgment of voter rights, over 75 percent of the family populations currently in the [district] have been deprived of voter representation. That’s over 100,000 students and their families being disenfranchised.”

The San Diego County grand jury, which investigated the district’s election process, found merit to some of the group’s complaints.

“As a result of the existing election process, some problems have emerged,” said a May 2017 Grand Jury report. “The diversity within the [district’s] student population has not always been reflected among school board trustees.”

The report recommended that board trustee candidates be elected only from within their home sub-district, and that would assure specific concerns of each region are represented.

A sole, sub-district election would help bring a more diverse list of trustees to the board, Caslavka said, since city-wide elections are expensive and are more likely to favor incumbents with name recognition or candidates with financial support from unions and special interest groups.

According to the grand jury’s investigation, elections can cost anywhere from $500 to more than $350,000, and some candidates are overwhelmed by the financial burden and energy required for two separate elections.

“Also, candidates must appeal to more than 300,000 registered voters in the second, city-wide campaign, a far greater number than in their sub-district,” the report said. “Name recognition can add a tremendous advantage … a study has shown school board incumbents have an 80 percent edge for reelection.”

The city has no oversight over the district, but any changes to the district’s election process requires an amendment to San Diego’s city charter.

In January, the council’s rules committee voted against four election reform proposals, including one calling for sub-district elections.

Council members voted 5-3 Monday to put term limits for school board trustees on the November ballot. The is group asking council to give voters the choice for sub-district elections as well.

The letter requests a response by Aug. 2, four days before the deadline for changes to the ballot.