"The continual subjugation of the masses depends on competition and internal disunity. As long as discrimination exists, and racial or ethnic minorities are oppressed, the entire working class is oppressed and weakened. This is so because the Capitalist class is able to use racism to drive down the wages of individual segments of the working class by inciting racial antagonism and forcing a fight for jobs and services. This division is a development that ultimately undercuts the living standards of all workers. Moreover, by pitting whites against Blacks and other oppressed nationalities, the Capitalist class is able to prevent workers from uniting against their common class enemy. As long as workers are fighting each other, Capitalist class rule is secure."
January 1, 1970
https://en.wikiquote.org/wiki/Racism