OK. Then, where does it say in the Constitution that there are conditions on citizenship when the word 'people' is used everywhere?
Sorry, I should have written this more clearly, as in “conditions of entry” and “citizenship” not “conditions of entry” and “conditions of citizenship.” Clearly the individual states cannot confer federal citizenship. The Constitution basically assumes that free people born here were automatically citizens, Amendment XIV subsequently extending birthright citizenship to freed slaves.
Article I, Section 8 addresses citizenship in terms of establishing “a uniform rule of naturalization.” Establishing conditions of entry, e.g., immigration law, is also a legislative function. These days one almost wishes it weren’t, but I digress...
Regarding “the people” and citizens, I would argue thusly. One, the Declaration of Independence states that “all men are ... endowed by their Creator with certain unalienable rights.” In other words, God grants rights, not governments, and He grants them to all, not just Americans.
Two, the Constitution confirms those rights and charges the government established by it with securing “the blessings of liberty to ourselves and our posterity.” That is, it is the duty of government to protect and ensure our rights, not to trample on them and not to attempt to extend them missionarylike beyond our shores (as John Quincy Adams stated, America “is the well-wisher to the freedom and independence of all. She is the champion and vindicator only of her own”).
Three, because God-given rights are universal, it would be unseemly for the Constitution to “secure” them only for citizens and not also for noncitizens residing in the US. They are “human rights,” as it were, not simply prerogatives of citizenship. Noncitizens cannot be “second-class citizens” (pun intended) where God-given rights are concerned.
This, I suspect, may be one reason why the Founders employed the language they did (”the people” instead of citizens). Note also in this connection that voting is NOT identified as a God-given right in the Constitution, rather it is established statutorily (Amendment XV extending the franchise to former slaves) and restricted to citizens (initially to land-owning, tax-paying adult male citizens). So, while all residents enjoy the God-given rights enshrined in the Constitution, only citizens may vote.
One of these days I’d like to explore this matter more thoroughly but this theory is certainly congruent with the language used and the political philosophy of the Founders. Does this clarify matters?