Chris Zhang, a soft-spoken tech attorney who’s running for one of three seats on the Cupertino Union School District board of education, would rather talk about how to improve curriculum and boost test scores than a violent episode from his past.

But Zhang has been forced answer questions about whether it’s appropriate for him to run for elected office, let alone hold a seat representing the interests of young children.

In 2009, an infuriated Zhang, then 35 years old, marched down to a badminton class to confront a man he knew on the Internet as George Wu, an online comments moderator for a Chinese immigrants forum.

Zhang, who kept arguing with other users on the website, was kicked off for, self-admittedly, “being abrasive.” But then he started directing his angst at Wu, sending him increasingly nasty comments, like, “Fuck your mother for being an unfair bitch … I’ll fuck you up,” and, “You better not run into me in real life … I got your picture now, you little piece of shit.”

Unlike most online trolls, Zhang made good on his threat. He tells San Jose Inside that he tracked Wu down through a message board comment saying that Wu was going to play badminton that day in Milpitas. Zhang went down to tell him off and rough him up, he says. When he arrived, he put his arm around Wu and said in Chinese, “Do you know who I am?” That set off a scuffle that left both men with swollen wrists.

According to court records, which Zhang doesn’t dispute, the school board candidate put Wu in a chokehold, pushed him to the floor, punched his stomach and somehow injured his wrist. “I don’t have a perfect past,” Zhang admitted to San Jose Inside, dismissing the incident as a symptom of him being “a reckless bachelor.”

Wu successfully petitioned for a three-year restraining order against Zhang. And Zhang? He says he accepts the legal consequences, adding that he’s now happily married with two little children.

That wasn’t a strong enough sell for Ro Khanna, who withdrew his endorsement after Wu’s restraining order came to light in the blogosphere in recent weeks.

On the other hand, Kansen Chu, a San Jose council member and state assembly candidate, says he stands by his endorsement. “I have known him as a family man,” Chu tells San Jose Inside. “I can accept his apology and give him a second chance. He is a different man today.”