1: Moreover , the surge of right-wing extremism that marked the 1990s had seemingly ebbed . 2: What the tragedies of 1995 and 2001 together teach is that the United States faces threats from multiple sources of extremism , all of which must be taken seriously . 3: Deborah Lauter and Mark Pitcavage : Right-wing extremism should still be taken seriously .
1: right-wing extremism 2: threats from multiple sources of extremism 3: Right-wing extremism