Slate has published a letter from Richard Posner criticising Scalia’s dissent on the Arizona immigration case. Posner is typically shallow in blathering uncritically about how immigration helps everyone.
Things get more interesting when Posner takes aim at Scalia’s statement that Arizona “bears the brunt of the country’s illegal immigration problem.” Posner rests his argument with what seems to be a simple error in arithmetic. He notes that “there are 10 million to 11 million illegal immigrants” in the country and then tells us that
As of last year there were estimated to be 360,000 illegal immigrants in Arizona, which is less than 6 percent of the Arizona population—below the estimated average illegal immigrant population of the United States.
Now, I make six percent of the current US population to be some 18.8 million, which is far more than 10-11 million. It follows that percentage of the population of Arizona that is illegal is higher in Arizona than it is in the rest of the country.
Now, Posner’s writing is unclear. One could also read his sentence as saying that 360,000 is less than the average number of illegals in a state, i.e. than 10-11 million divided by 50 ~= 200,000. This is also false: 360,000 is comfortably more than 200,000.
How did Posner not see this? How did his editors not see this? How stupid can our establishment overlords get?