This article maintains that power enhances consumers’ ability to resist social in- fluence but produces different resistance outcomes, depending on the level of certainty with which consumers hold their own attitudes. When attitude certainty is high, empowered consumers resist social influence by discounting others’ opin- ions. When attitude certainty is low, empowered consumers intentionally diverge from others’ opinions to signal their independence. Data from the first two exper- iments provide consistent support for the dual impact of power. The last two ex- periments examine the processes leading to the reactant response. Experiment 3 finds that the experience of uncertainty weakens empowered consumers’ confi- dence in their sense of power, leading them to perceive others’ unsolicited opinions as a threat to their autonomy, which then triggers the reactant response. Finally, consistent with a self-presentation interpretation of reactance, experiment 4 finds that power leads to reactance when evaluations are public but not when they are private.