Back in January, after Donald Trump had nominated Steven Mnuchin as treasury secretary, I uncovered a leaked document from the California attorney general’s office that showed OneWest Bank repeatedly broke foreclosure laws under Mnuchin’s six-year reign as CEO and then chairman. Prosecutors in the state’s Justice Department wanted to file a civil enforcement action against the company for “widespread misconduct,” but the attorney general at the time, Kamala Harris, overrode the recommendation and declined to prosecute. She never gave a reason.

Months later, this revelation has been granted new life, wielded as a political weapon by those who oppose Harris’s possible presidential run—most prominently in Ryan Cooper’s column in The Week about why “leftists don’t…