This chapter discusses arguments in favor of the thought that exclusion itself is incompatible with liberal justice; all borders, on this analysis, would be open in a just world. The chapter examines the concept of justice, as given in John Rawls, and then uses this concept to discuss why arguments in favor of open borders won’t work. Four arguments are discussed: the arguments from arbitrariness, from distributive justice, from coherence with existing rights, and from the injustice of coercion. None of these, the chapter concludes, pay adequate attention to the uniquely political nature of the relationship of fellow citizens.