What we actually see is that in 1957, the median income was $5,000 and that 1.85% of the population earned more than $15,000. In 2008, the median income was $50,000 and the percentage of the population earning more that $150,000 was 20.6% (sources: http://www2.census.gov/prod2/popscan/p60-030.pdf
). To me, that suggests that your assertion is not just incorrect but way off base. One could do more sophisticated analyses, and factor in more variables, but there is no question that, by any reasoned measure, that income has shifted dramatically toward the wealthiest segments of the population over the last 50 years in America which is incompatible with the notion that we have become more socialist in the same period.