Racial discrimination continued to be enacted in new laws in the 20th century, for instance the one-drop rule was enacted in Virginia's 1924 Racial Integrity Law and in other southern states, in part influenced by the popularity of eugenics and ideas of racial purity. People buried fading memories that many whites had multiracial ancestry. Many families were multiracial. Similar laws had been proposed but not passed in the late nineteenth century in South Carolina and Virginia, for instance. After regaining political power in Southern states by disenfranchising blacks, white Democrats passed laws to impose Jim Crow and racial segregation to restore white supremacy. They maintained these until forced to change in the 1960s and after by enforcement of federal legislation authorizing oversight of practices to protect the constitutional rights of African Americans and other minority citizens.

Answer this question, if possible (if impossible, reply "unanswerable"): What had popularity in the early 20th century that caused rising racial discrimination?
eugenics and ideas of racial purity