Russian domination of the Comintern rekindled rival nationalisms inside the American party.

Evidence

In a movement dominated by national parties and subparties, the character of the Comintern and the consequent inflation of the political influence of Russian nationals in the United States was bound to produce or revitalize counter-nationalisms. The growing power of specifically Russian Jews in the movement created or exasperated cleavages within the Communist movement that were not resolved even by the late 1920s. — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 996