  Joseph Carens offers an answer to this question by invoking the standard distinction between public and private spheres. He writes, “There is a deep tension between the right of freedom of association and the right to equal treatment. One way to address this tension is to say that in the private sphere freedom of association prevails and in the public sphere equal treatment does. You can pick your friends on the basis of whatever criteria you wish, but in selecting people for offices you must treat all candidates fairly….So, the fact that private clubs may admit or exclude whomever they choose says nothing about the appropriate admission standards for states. When the state acts it must treat individuals equally.” (Carens 1987: 267–8) This answer is promising, but even if one is generally sympathetic to the public/private distinction, it is not obvious that it applies to admissions into a country in the same way that it applies to decisions regarding those already within this state. This is because, many presume that in order to be legitimate, states must treat all of their constituents as free and equal, and one way to pursue this freedom and equality is to ensure that individuals are not excluded from various spheres of power and prestige on the basis of their membership in historically disadvantaged groups. But because states need not ensure that their constituents are free and equal to all outsiders, it does not have the same reason to protect against foreigners being excluded on the basis of characteristics that would rightly be ruled out if used by public groups within the state.