Joe Biden stands by comments linking Trump to growth of white supremacy

A new poll shows former vice president Joe Biden leading the Democratic field in Iowa. On Thursday, Biden repeated his claim that President Trump encourages white supremacists. Sen. Elizabeth Warren is now in second, up 12% from where she stood with voters four months ago. Sen. Warren is also campaigning in Iowa, and was one of the first Democratic candidates to say the president is a white supremacist. Ed O’Keefe reports.