Longtime white supremacist James W. von Brunn opened fire at Washington, DC's Holocaust Memorial Museum on Wednesday, killing a security guard and injuring another. It was the third recent shooting involving a gunman with ties to the white nationalist movement, following last month's slaying of abortion provider Dr. George Tiller and the shooting of three police officers in Philadelphia in April. We speak with one of the nation's leading researchers on right-wing hate groups, Leonard Zeskind, author of Blood and Politics: The History of the White Nationalist Movement from the Margins to the Mainstream. Zeskind has been closely monitoring white nationalist and anti-Semitic groups for over thirty years.