It would be ideal if all miscegenation and all immigration were to cease, assuming that the perpetuation of humanity and the cultivation of human excellence are desirable. Firstly, it is best not to put all of our eggs in one basket. If different states were to be made discrete, their populations would diverge, giving an advantage in surviving some catastrophe, like a global pandemic. The obvious advantage would be that it would be more difficult to transmit it from one place to another because there would be less travel and a great reduction in immigration. Additionally, over several generations, it is likely that populations would diverge genetically to an extent that it would be more probable that at least one would survive and carry the torch into the future. Furthermore, this arrangement would have the benefit of developing populations with different strengths. Surely it is advantageous for humans to attempt advance in as many different ways as is reasonably possible, instead of as few. Moreover, institutes could be set up within each state to track cultural progress. In other words, each state would be an experiment. We would be able to learn which social and political policies were effective in certain circumstances and which led to disaster. This would have the effect of making governance more scientific and less speculative. One need not oppose all outbreeding, but it should be controlled. It is idiotic to allow populations to mix with one another indiscriminately without considering how their genetic profiles will combine. Hybridization should be scientific, obviously. Agree? Disagree?