In the terminology of white supremacy, "Mud Race" refers to any non-white ethnic/racial group, other than Jews, such as Africans, Asians and others. "Mud races" are considered to be pre-Adamic and lacking souls. Race mixing with mud races to be strictly avoided by whites, because it will lead to dilution, denigration and dissipation of the white race.
Jews are particularly singled out in the white supremacist cosmology as the direct descendants of Satan.