One of the many problems highlighted in the article is this one:
A conservative—I had better say, paleoconservative—acquaintance of mine is fond of saying that the two body blows against the USA in the past half century were, first, the 1965 Immigration Act, which fired up the odious doctrine of multiculturalism, and second, the Griggs v. Duke Power decision of 1971.
The second of those is of course much less well known than the first. It essentially rules that Title VII of the 1964 Civil Rights Act forbids employers giving aptitude tests to prospective hires. In other words, it forbids an employer from trying to find out how smart you are before hiring you.
The message of Griggs and "disparate impact" theory: if minorities fail tests at a higher rate than whites, it's the test that's wrong.
Steve Sailer wrote about the Griggs decision in April, 2005: End The April Agony—Bring Back IQ Tests!