This is the first book by Buchanan I have read. In the past I viewed him as correct on the immigration issue but too focused on the cultural aspect and not focused enough on the anti-labor and anti-environmental effects of immigration policies touted by those who fradulently define themselves as "pro-labor" and "Green".
But from reading this book I believe he does have a valid point to make.
I believe perhaps the biggest intellectual contribution he makes to these issues is his discussion of what is the nature of American nationhood. He makes some compelling arguments that the Neocon notion, which is the intellectual underpinning of right-wing open-borderism, that the nature of American nationhood is simply one of ideas, is incomplete at the least and perhaps downright false. His view of the core of nationhood is, as he quotes from someone on the other side, rooted in "blood and soil".
I am not totally convinced, but he does provide powerful supporting arguments for his point of view based on a mountain of examples from throughout the world.
As far as I can tell, Buchanan does not say that there is necessarily anything meritorious about nationhood being defined by "blood and soil" rather than "ideas", but, his core point is, that is the way the world works, and those who wish our nation to be governed based on a falsified view of reality are planting the seeds of disaster.
Of course, as it relates to immigration policy, the notion of what is the nature of our "nationhood" is not necessarily a central issue, because the open borders policies adovcated by the "axis of extremism" (my term for the open borders coalition of the radical left and radical right) are fatally flawed on so many levels that they would be disastrous even if the flood of illegal aliens entering our country were amenable to becoming supportive members of a society based upon the ideals our nation is intended to aspire to- such as equality, justice, and tolerance.
All in all, there are many books which have come out recently that relate to the illegal alien invasion of America, and Buchanan's is one of the better ones, and, equally important, it has achieved a popular following that puts it in a good position to serve as a strong positive force in advancing the popular uprising around the country that is demanding a more progressive and sustainable immigration policy for our nation.