I think the immigration issue is more complicated than the Future of Freedom Foundation, Trumpistas or Hoppe would frame it. I don't regard the UK (or US) government as having any legitimate authority, nor do I regard any increase in the activities of the police as desirable. While people should be allowed to exclude or discriminate against anyone they please that does not give them the right to exclude them from the property of other people or uninhabited land.
This latter point is especially salient to the USA - the vast majority of the USA is totally uninhabited wilderness. This can be settled by anyone, at any time, and no one else has the authority to prevent them. I have no problem with an Islamic Caliphate in Wyoming, as long as they're not attacking other people. Certainly all 'Federal' lands are completely without owners, and ought to be open to settlement by all people, including the Chinese, ISIS and Mexicans.
Furthermore, I would argue that a lack of consensus and social cohesion is a good thing, on the large scale - it checks the loyalty to the central state and creates political divisions, sometimes irreconcilable. Anything that weakens the central government is, prima facie, a good thing.
While it cannot be denied that the US, UN and various European governments subsidize the importation and settlement of foreigners, this in itself does not legitimize the deportation or blockage of these people - anymore than collecting a welfare check is a legitimate reason to deport native-born Americans.
Put simply, the US government subsidizes and taxes every imaginable group, and being opposed to immigration on the principle of 'citizen-taxpayers' ignores the fact that no one really has a legitimate claim to 'public land' as it presently exists. The huge buckets of money that are sloshed around the USA by various tax-and-spend plans can not be meaningfully traced back to any person, nor can any person be shown to unambiguously be a 'tax consumer' as opposed to a 'tax payer'.
Even if it could, there are clear conflicts within these groups - many people obviously DO want immigrants coming into the United States, and they often live in the same locality as people who do not want immigration. If there were actually uniform opposition to immigration by everyone in the city of Dallas then a general exclusion could be justified. But given that many firms in Dallas would love to have low-wage employees, and many liberals in Dallas would love to see more diversity, this is a purely hypothetical exercise.
The only way 'immigration' can be sorted out other than one group of ethnic chauvinists and class elites imposing themselves on another is for a thorough decentralization and privatization of all the regions concerned. But if this were to happen you could kiss 'white America' goodbye - while some regions would remain predominantly white and perhaps even racially segregated the vast majority of the empty countryside would quickly be filled up by enterprising frontier-folks who - by sheer demographic ratios - would mostly be Latin Americans and Asians.