Insurrection peaks coincided with capital expansion that co-opted moderates

Evidence

The most radical phase of the Civil Rights Movement and the Black Nationalist Movements in the 1960s had coincided, paradoxically enough, with the phase of the most dynamic growth and expansion of American capital, thanks to the long wave of the postwar boom, the expansion of the military-industrial complex because of the Vietnam War, high rates of employment and spending, the still-existing US hegemony over its own capitalist partners as well as the world market generally. As a result, the system had at that particular juncture, before the crises came in the 1970s, a historically unprecedented capacity to absorb domestic challenges by incorporating into the margins of its own institutions the more professionally inclined elements of the radical intelligentsia, while the isolation through selective terror of the less compromising individuals and segments was facilitated by their relative isolation caused precisely by the increasing incorporation of the rest. — Aijaz Ahmad, In Theory, 140