The suspected gunman in Saturday's shooting in Buffalo, N.Y. is alleged to have written a racist screed explaining his motivations. One of the topics discussed is "replacement theory," a talking point that has made its way to statements made by Republican lawmakers and Fox News hosts despite its past as a fringe idea in racist forums. Today, a look at what replacement theory is, how it became amplified & what implications that has on the political process.This episode: White House correspondent Tamara Keith, national political correspondent Mara Liasson and national security correspondent Odette Yousef.Support the show and unlock sponsor-free listening with a subscription to The NPR Politics Podcast Plus. Learn more at plus.npr.org/politics Connect:Email the show at nprpolitics@npr.orgJoin the NPR Politics Podcast Facebook Group.Subscribe to the NPR Politics Newsletter.Find and support your local public radio station.