Public reason accounts commonly claim that exercises of coercive political power must be justified by appeal to reasons accessible to all citizens. Such accounts are vulnerable to the objection that they cannot legitimate coercion to protect basic liberal rights against infringement by deeply illiberal people. This paper first elaborates the distinctive interpersonal conception of justification in public reason accounts in contrast to impersonal forms of justification. I then detail a core dissenter-based objection to public reason based on a worrisome example (...) advanced by Jonathan Quong. While we may be able to impersonally justify coercing the illiberal dissenter, public reason liberals must explain how we can interpersonally justify such coercion—meaning justify given the perspective of the dissenter. The two prominent strategies for dealing with dissenters involve idealization of reasoning and requiring liberal values; I show that these strategies do not succeed in a way compatible with the public reason project. That is, the prominent strategies leave public reason theorists with a dilemma between denying the legitimacy of using coercion to protect core freedoms against deeply illiberal people or abandoning the fundamental public reason project. I conclude by proposing a different answer to public reason liberalism’s fundamental question: what requires justification? On my account, it is not that coercion requires interpersonal justification for its permissibility, but that such justification is necessary as a constitutive element of a kind of moral community. (shrink)