Authorities purport to rightfully possess the power to give their subjects reasons to obey their directives. Whether they legitimately possess this normative power depends on whether the relevant justificatory standard is satisfied. Whatever the content of this standard, need it only be satisfied in the actual scenario in which the exercise of authority is taking place? Or does legitimacy also require justification across a range of relevant counterfactual scenarios? This paper investigates these questions with reference to Philip Pettit’s theory of robustly demanding goods. Specifically, it evaluates the viability of applying Pettit’s account to existing moral or conventional justificatory standards of legitimate authority.