Abstract. Prominent normative theories for accommodating minority national groups appeal to the value of national cultures and/or the psychology of group recognition. This article hopes to show that an argument from political authority provides a better justification. Building on Joseph Raz's theory of authority, the article argues that members of minority national groups are disadvantaged relative to their majority counterparts under standard democratic institutions; such institutions do not provide minority national groups with comparable access to the conditions for legitimate political authority. Constitutional arrangements for accommodating minority national groups -such as territorial selfgovernment or power-sharing -are justified then in so far as they might ameliorate this disadvantage.