Take a guess: What is the average IQ of a white dude who lives in a trailer? According to the GSS, it's 93.1. It's 85.5 if you're black and 88.6 if you're Hispanic.
Whites who live in mobile homes are not average whites in terms of IQ. They are lower- or working-class people. Blacks and Hispanics, on the other hand, who live in trailers have IQs typical for their respective groups.
This helps give us an image of the kind of America we are becoming as the country Latinizes. Instead of a traditional America which has been middle-class, we're headed toward Trailer Park America.