The Left has always placed great importance on using the schools to attain its ends. Socialist governments almost always take control of education away from Churches and religious orders. In communist countries it was banned entirely. Control over the formation and education of youth, and therefore their spiritual and philosophical worldview, is the single most important factor in bringing about the triumph of socialism.
As part of the broader socialist movement, progressive education “reformers” see education as a useful means to build a socialist society, making it more egalitarian, atheistic, and centrally controlled. They see the influence of Christianity – as well as the family, tradition, and Christian culture – as the greatest obstacles to this end. According to the Left, education should serve to inoculate a child from these supposedly destructive influences, freeing him to embrace his true role, that of a cog, a worker, and a faceless member of the masses -- or, as the Common Core architects would say, a member of the “twenty-first century global economy.”
https://www.tfpstudentaction.org/blog/a-brief-history-of-progressive-education
