Michael Chang, a moderate voice on the volatile Santa Clara County Board of Education and a catalyst for Asian-American political participation, has stepped down from his seat, citing family reasons.

His resignation, with a year remaining in his second term, could portend board gridlock on charter schools and other hot-button issues.

“I have to cut back on certain things,” said Chang, 60, noting that his mother suffered a severe stroke in October. He visits her daily in Pacifica. He’s still working as a full-time instructor at De Anza College, and runs a leadership training institute. So with meetings that stretch from late afternoon to sometimes late evening, he said, “the county board just doesn’t work for me.”

In a letter last week, Chang wrote, “I can no longer devote the necessary time and energy to my board duties. Hence, it is with a heavy heart that I must submit my resignation from the board, to be effective immediately.”

Board President Rosemary Kamei said she was “very saddened by his resignation.”

“He provides a balance on the board and is very thoughtful in his decisions,” Kamei said. “We will miss that a lot.”

Chang has been a critical swing vote on a board that has split, sometimes acrimoniously, in recent years. The board plays a limited but influential role in countywide education, particularly in reviewing charter school petitions, often those that have been turned down by boards of local school districts. It’s historically been more charter-friendly than local school boards to charter schools, which are public schools run by private groups rather than by school districts.

For the past year, Chang as president of the county board of education tried to corral trustees as they wrestled with evaluating and, ultimately, parting ways with former Superintendent Jon Gundry.

“He’s been great, very patient, and works well with people — board members and the public,” said trustee Grace Mah.

But the animosity and assertiveness among board members reportedly wore on the mild-mannered Chang.

On Wednesday he denied that the board’s yearlong struggle, over 22 meetings, played into his decision to step down.

“Sometimes people get a little too impassioned,” he said, “but I have never questioned the sincerity that people bring to the board.”

Yet perhaps hinting at his colleagues’ behavior, Chang advised them in his email, “As remaining board members, I hope that you will redouble your commitment to work together to serve the needs of students.”

Already, the board has hinted it may not heed that advice. After selecting Kamei to succeed Chang as board president, it failed to choose a vice-president, deadlocking 3-to-3 on votes for trustees Claudia Rossi and Joseph Di Salvo.

Chang jumped into politics in 1991 when he successfully ran for the Cupertino Board of Education. At the time, he was only the second Chinese-American trustee serving in Santa Clara County.

He then set out to round up and train more Asian-Americans to seek political power. In 1997 he established an institute at De Anza College to attract and prepare potential candidates.

“In the early days we took whoever was breathing, and we were happy,” Chang said in a 2016 interview. His Asian Pacific American Leadership Institute claims 1,200 alumni and more than 250 serving in government and non-profit groups. Among them are Assemblyman Evan Low of Campbell, and San Jose-Evergreen Community College District trustees Huong H. Nguyen, Wendy Ho and Mayra Cruz.

“I learned a lot from him,” said Camille Llanes-Fontailla, executive director of the community group Somos Mayfair in San Jose. “I’m very grateful to the work he’s done.”

Chang later served on the Cupertino City Council, and was elected to the county school board in 2010 to represent Trustee Area 2, which covers the West Valley — areas encompassed by the Los Gatos-Saratoga Union High School District, and small portions of Santa Clara Unified and Fremont Union High School districts.

At its next meeting, Jan. 17, the board will discuss whether to fill Chang’s seat by appointment or special election. The term extends until the end of 2018.