Here is how Their ABC described a program about open borders, with guess Dr Sarah Fine of King’s College London:
  https://www.abc.net.au/radionational/programs/philosopherszone/keeping-them-out/10169906

“Most people agree that nation states don’t have any moral right to control the movement of citizens within their borders, or to prevent citizens from travelling beyond those borders. So why should we accept that states have the right to exclude or restrict entry to refugees and immigrants? The answers usually appeal to security, or the need to 'preserve' national values and culture. But these arguments may be less robust than they appear.”

     That is common argument made by the open borders religious sect, that if free movement of citizens is allowed within borders, how, morally can states justify restricting people coming in. Hence, open borders. Well, tell that to China, but, of course, all of this sort of stuff is never directed to anyone except the West, and white people, where the liberal Left raise these sorts of questions. Oh, states do restrict movement of citizens within borders to some degree, usually for security purposes, so we need not grant the opening assumption. As for ethics and morality – don’t make me laugh, only philosophers in well paid ivory towers worry about that, for in the real world, politics rules, and ethics and morality are just idle talk. For example, how ethical is it for philosophy departments to exist, and for people to do paid philosophy, when there are starving Africans who could survive with their money? Why, there are even philosophy books about this:
  https://global.oup.com/academic/product/the-moral-demands-of-affluence-9780199258116?lang=en&cc=au

     Sarah Fine has put the case against immigration restriction, in her paper “The Ethics of Immigration: Self-Determination and the Right to Exclude,” Philosophy Compass, vol 8/3, 2013, pp. 254-268, and she has a forthcoming book Immigration and the Right to Exclude with Oxford University Press. She raises numerous critical arguments against a state’s right to control its members, such as if states have a right to control membership, then how does this justify a right to control immigration? Well, open borders simply change entire countries, racially and culturally, as we document here each day. Move every fundamentalist Muslim, supporting sharia law into King’s college London, and it may not be possible for a woman to work as a philosopher. Oh, but we can’t argue that way in academic journals, can we? Well, we are not academics here.

     However, Fine has a direct attack on the closed borders view, summarised here:
  https://stephentweedale.wordpress.com/2018/09/20/sarah-fines-democratic-argument-against-the-right-to-exclude/

1. To exclude a person from immigrating is to govern them.

2. Excluded migrants do not have a say over the policies that exclude them.

3. Excluded migrants are governed without having a say in how they are governed. (from 1 & 2)

4. Government authority is legitimate only when it is exercised over people who have a say in how they are governed.

5. Governments may not legitimately exercise their authority to exclude migrants. (from 3 & 4)

     This critic giving the summary argument, shares the same scepticism that Fine has in justifying immigration restriction, but is concerned that the argument above could justify internal restrictions on movement. We need not consider this here, but it does show how “clever” philosophical arguments can come unstuck, in unexpected ways. What we should do is reject every one of Fine’s premises, and the burden of proof is upon her, unlike her criticism of the self-determination argument, where she can sit back and fire burden of proof considerations at immigration restrictionists. In general, once philosophers have to justify anything, their castle of glass cracks and shatters pretty quickly.

     To exclude a foreign person is to “govern” them? No, that is nonsense. The exclusion is nothing to do with “governing” as the word is ordinarily defined, which is a term referring to the policies, actions of a state. The exclusion is simply a consequence of existing law, and that is a much wider concept. Overseas people can and are subject to laws made in other jurisdictions (such as aspects of free speech), even if the jurisdiction cannot directly enforce those laws, all with no say of people at all. Once an offending person sets foot in that jurisdiction, they are gone. And, even if the meaning of the word “governed” is stretched, it is absurd to claim that excludes potential migrants who have no say about immigration policy, because these people, and their liberal lawyers and academics, never stop talking and trying to undermine immigration law, and invading societies regardless of law, solely for their economic benefit. Witness what was done to Trump’s policies by these hostile academic elites. And, it simply begs the question to suppose that aliens have some right of say about a counties immigration policy. Why should I have any right to determine, or undermine China’s immigration policy? Whatever happened to: it is none of our business? In the past, this claim would have been instantly laughed at.

     Premise 4 is a joke, since the local people have not been given a say about the mass immigration which has occurred in the post-World War II period. Hence, those governments, often engaged in actively changing the ethnic profile of nations, are illegitimate by that premise, but that is, I suppose, not intended. Locals have no rights, only the magical migrants. Fine’s argument would also undermine the right of Israel to exist. I rest my case.