Encore Thursday, Dec. 16, 2021 at 10 p.m. and Monday, Dec. 20 at 4 p.m. on KPBS 2 / no longer available on demand. After WWI and WWII, Reinhold Niebuhr became the voice of conscience to an America reaching the pinnacle of its economic/political power and has influenced leaders such as Martin Luther King, Jr, President Barack Obama, former President Jimmy Carter, and others.