Immigration as it exists in the capitalist world is not really desirable, be it for the immigrant workers , the native workers, or the workers in the country that the immigrants came from.
I feel allot of misunderstanding about it comes from the fact that people don't really understand the material conditions that drive it.
The reason that our liberal governments tolerate it, is because capitalists desire cheaper, more available and less organised labour.
They also tolerate it due to the demographic issues generally facing post-industrialised nations; due to reducing fertility, the working population is stagnant or shrinking; this is downward pressure on the availability of labour.
The appeals to morality and liberty are mostly a smokescreen, much in the same way that Neoconservative ideology is just a smokescreen for aggressive imperial foreign policy.
That's not to say that immigration is always bad, it's just that in our day it's mostly driven by economic incentives that exist because of Imperialism; it just represents another way that communities are pulled apart by capitalism.
Cerrtainly huge numbers of people would have to be moved around this century under socialism, as the climate and coastlines change.
Tucker is of course full of shit, his Ideology is not consistent at all so it's right to view him with extreme suspicion.
He makes the same mistake that all the anti war liberals and libertarians make, which is that the wars as are bad not because of the huge number of people who die, but becausy the military 'costs too much' and the wars are a 'waste of money', it's this belief that the MIC is the cause and not a symptom of American imperialism (see also Israel as the cause and not a symptom of US imperialism).
Another perfect example is this analogy I saw from a Succ Dem; when told that welfare was much more expensive than the military budget, the Succ dem responded by saying that the welfare was like paying for rent and groceries whereas the military is like buying a handgun; sure the handgun is cheaper, but your rent and groceries are much more important.
The problem is that the US is not some average well meaning citizen in this analogy. The US is more like a mob boss, running a giant extortion racket using the threat of violence, a gun is a solid investment for this guy.
Infact without having that gun he would have never got to that position in the first place.