in the wake of the el paso shooting, renewed attention is being paid to the white nationalist conspiracy theory that white people are being replaced by people of color. this is leading some to believe that president trump's words on immigrants and the border crisis are lending legitimacy to the racist narrative. joining me now to discuss is ruth ben-ghiat, a professor of history at nyu, and cnn presidential historian doug brinkley. so glad to have both of you on. thank you so much. ruth, i'm going to start with you because you say the president's racially charged rhetoric is strategic telling "washington post," quote, "this is a concerted attempt to construct and legitimize an ideology of hatred against nonwhite people and the idea that whites will be replaced by others.