Chapter 4 spotlights migration policy that seeks to exclude by limiting those who practice certain religions from gaining admission to a territory. We consider: What is wrong with a ban on Muslims? Is a ban on Muslims impermissible because it violates human rights? While some think it is difficult to make such arguments directly, this chapter offers an argument that is grounded in core aspects of the practice of human rights. Drawing on core elements of the argument discussed in Chapter 3 concerning the conditions states must satisfy in order to exercise power legitimately, we see that there are important internal and contribution requirements that enacting a Muslim ban fails to meet. Indeed, a legitimate state cannot embrace a migration policy that bans Muslims from being admitted without such policies undermining the state’s claim to legitimacy.