"Immegration Invasion" is a propagandistic polemic. It presents an argument, and so it is appropriate to review it in that light.The chief flaw in the authors' argument is that they have completely ignored the human right to Liberty, which is, by act of the U.S. Congress, an unalienable right. In the 1930s, the govt of Germany came to regard Jews as the source of great difficulty, and with this as justification, the govt abridged their liberties. The authors of "Immigration Invasion" regard immigrants as the source of great difficulty, and they urge the govt to abridge the liberties of immigrants. The authors discuss the right of Liberty not at all, and they mention human rights only when they denounce the ACLU for using "human rights" as a pretext. Liberty encompasses the right of peaceful individuals to move about freely, without interference from the govt. It is a basic human right, and the authors of "Immigration Invasion" ignore it.
"Immigration Invasion" has other flaws. From the start it shows profound bias, repeatedly referring to immigrants in pejorative terms, and describing migratory behavior in terms of catastrophe, usually as a "flood". The premise that migration is tantamount to military invasion is preposterous and would justify treating the migrations of songbirds as military invasions as well.
The authors have a poorly conceived economic theory that includes the assumption that the number of jobs in the U.S. is limited. In the 1990s, immigration to the U.S. has amounted to more than a million persons per year, yet unemployment rates are the lowest in decades. Immigrants contribute the labor to provide the goods and services they use, and they thereby expand the economy and the number of jobs to fit the expanded population. The authors are plainly wrong in their assessment of the economic effects of immigration.
The authors repeatedly describe costs that immigrants bring to "taxpayers". Immigrants are taxpayers, subject to tax laws just like everyone else, but the authors consistently overlook that and other facts inconvenient to their views.
In summary, the authors have neigher ethical nor economic basis for the views they present. They aim to suppress liberty, and the book is propaganda.