Members of both the U.S. Senate and House of Representatives should read "IQ and the Wealth of Nations." The book is widely regarded by a number of leading academics. Even through some Members of Congress may not agree with the underlying premise, it is important for the to be exposed to this and other texts.
I do not believe that everybody in Congress should have to read the 'IQ and the Wealth of Nations'. I think that Congress has a lot more issues and problems that will not be solved by merely reading something like that. I've read it, and I can say that it will not help.
While it may be a good book that has a great deal of insight to offer, people should not necessarily read it. Also, I don't see how its relevant for politicians to read, as its not really a book on policy or governance. And finally, it looks like there is a great deal of criticism of this book and its methodologies.
Dr. Sowell points out in his studies on the issue of IQ that the aim studied by Lynn concerning IQ tests and the Wealth of Nations is confusing correlation with causation. Nations with better GDP also boast higher IQ scores, but it is because prosperity results in a greater focus and value on education, one cannot put the cart before the horse and presume that education (or as some have suggested genes) is the issue needing address.
While both those works are well written and have deep economical and political meaning there would be a large number of people in Congress that would disagree with the contents of them, I don't see what good it would do to force those people to read the books when you know they will just disagree with them anyway.