There wasn’t much to celebrate in Michigan’s statewide reading and math assessments this year. No grade level in the state reached 50% proficiency in any subject on the Michigan Student Test of Educational Preparedness, or M-STEP, according to results released in August. But Nikolai Vitti, who heads the state’s largest public school system, hasn’t lost hope.

When he became Detroit’s superintendent in 2017, Mr. Vitti inherited a crisis. By 2010 the city’s population had shrunk nearly to the size it had been a century earlier...