In a rare and wide-ranging interview, the attorney general disclosed chilling, new details about the evolving threat of homegrown terror, and touched on topics ranging from Wikileaks to the prisoners at Guantanamo Bay.
What was uppermost on his mind, however, is the alarming rise in the number of Americans who are more than willing to attack and kill their fellow citizens.
"It is one of the things that keeps me up at night," Holder said. "You didn't worry about this even two years ago -- about individuals, about Americans, to the extent that we now do. And -- that is of -- of great concern."
"The threat has changed from simply worrying about foreigners coming here, to worrying about people in the United States, American citizens -- raised here, born here, and who for whatever reason, have decided that they are going to become radicalized and take up arms against the nation in which they were born," he said.