Something that deserves more attention when discussing the allegedly declining fate of less educated white Americans is that this is a shrinking share of the white population. Here courtsey of the Census Bureau is data on the average educational attainment of white men in the United States (PDF) and the trends are quite striking. Forty years ago a white man was more than three times as likely to drop out of high school as to finish college, whereas today he's more than twice as likely to finish college as to drop out of high school.
That's a big deal, and it seems to me that it has to be part of the context for evaluating trends in average outcomes for the less educated slice of the population. College is in part about learning and in part about selection and screening. Back in 1970, a white man at the 80th percentile had probably been screened out of the college pool whereas in 2010 he's probably been screened into it.