Left-wingers have a long history of committing political atrocities that have resulted in the deaths of thousands to millions; from the Reign of Terror all the way up to the Cambodian Genocide.
Communism as a murderous ideology is also a dying ideology.
The Atlantic slave trade and the mistreatment of First Peoples of the Americas both killed millions -- and we hardly see those as a current threat of mass death. Christians are culpable for the Crusades, witch hunts, and the Inquisition. No Christian organization now endorses those.
Extreme leftists have become irrelevant as genuine threats of mass murder. Organized crime, which is difficult to place on the left-right continuum, is now far more likely to cause death than extreme leftists in America. Bloods? Crips? MS-13? Much more dangerous than old left-wing phantoms.
Hal Turner is a piece of work.
Agents-provocateurs are untrustworthy as a rule.