I think that's precisely right. A serious political history of the US in the second half of the 20th century would have that as its theme -- how the ideological rectification campaigns of the post-WWII US were contradicted by a slowly-developing left consciousness from the civil rights and anti-war movements -- and, when the counter-attack came (cf. The Crisis of Democracy, 1976), the rise of neoliberalism was crucially aided by a fifth column within the left -- identity politics.
One of the few recent books to call the outcome by its right name is Walter Benn Michaels' The Trouble with Diversity: How We Learned to Love Identity and Ignore Inequality (2007).
Noam Chomsky (among many others) commented on the matter a decade ago: "American society is now remarkably atomized. Political organizations have collapsed ... The left has a lot to answer for here. There's been a drift toward very fragmenting tendencies among left groups, toward this sort of identity politics" (Mother Jones, January/February 1996). --CGE