In the classic oligopoly games a Stackelberg leader often chooses exactly the action of an uncontested monopolist. We show that this is a theorem whenever the firms share an affine best response, characterize the demands that make best responses affine—linear, log-linear, shifted constant elasticity, and power demand, with strategic substitutes and strategic complements alike—and show that with such demand every firm can optimally ignore the future in any finite arrangement of sequential and simultaneous play whose simultaneous stages admit an interior equilibrium.