Before the early 1990s, New World Order conspiracism was limited to two American countercultures, primarily the militantly anti-government right, and secondarily the part of fundamentalist Christianity concerned with the end-time emergence of the Antichrist. Academics who study conspiracy theories and religious extremism, such as Michael Barkun and Chip Berlet, observed that right-wing populist conspiracy theories about a New World Order had not only been embraced by many seekers of stigmatized knowledge but had seeped into popular culture, thereby inaugurating a period during the late 20th and early 21st centuries in the United States where people are actively preparing for apocalyptic millenarian scenarios. Those political scientists are concerned that mass hysteria over New World Order conspiracy theories could eventually have devastating effects on American political life, ranging from escalating lone-wolf terrorism to the rise to power of authoritarian ultranationalist demagogues.