As the Star Tribune reported in 2018:
Tim Walz was an enlisted soldier in the Minnesota National Guard in 1999 and defensive coordinator of the Mankato West High School football team. A student at the school, where Walz taught geography, wanted to start a gay-straight alliance.
This was three years after the president, a Democrat, signed a law forbidding same-sex marriage. Soldiers suspected of being gay in Walz's own unit could be discharged from the military. But Walz, now Minnesota's Democratic candidate for governor, had seen the bullying some students endured and agreed to be the group's faculty adviser.
“It really needed to be the football coach, who was the soldier and was straight and was married,” Walz said. In other words, he would be a symbol that disparate worlds could coexist peacefully.