What Trump's response to white supremacist groups means

In the past, President Trump has failed to denounce far-right extremist and racist groups and sentiments when prompted. He did so again during Tuesday night’s first presidential debate, telling members of the white supremacist Proud Boys group to “stand by.” William Brangham talks to the University of Chicago’s Kathleen Belew and Janai Nelson of the NAACP Legal Defense and Educational Fund.