We don’t know for certain that controversial DC Schools Chancellor Michelle Rhee will depart DC when her boss’s term ends — and it will end soon — but it seems very likely. Assuming she does leave, there is a big education lesson to be learned from Adrian Fenty’s re-election loss: Relying on crusading politicians to successfully and permanently reform a government schooling monopoly is a recipe for crushed hopes. Politics is simply too volatile — and enacting tough reforms too politically risky — for even good reforms to be sustained. It’s just another reason that the key to truly sustainable reform is school choice, in which parents control education funds, educators have to compete and perform for business, and children are no longer buffeted back and forth by the ever-changing winds of politics.