The Classic party identification model originally derves from the work of Campbell et al. in the 1960sAngus Campbell, Phillip E. Converse, Warren E. Miller and Donald E. Stokes, The American Voter (New York: Wiley, 1960).In The American Voter Campbell et al. noted that there was a large disparity by age between, first, the number of voters claiming an Independent identification in the United States and, secondly, the numbers claiming a strong identification with one of the two parties.