"For decades now, America has dealt with supremacist religious ideologies and attacks that has influenced murders as far apart in time as the assassination of Martin Luther King, Jr. and as recently as the massacre at the AME church in South Carolina? More people in the U.S. have been killed by far right extremists than by those linked or sympathetic to current domestic attacks." That is the thesis of Stuart Wexler's new book "America's Secret Jihad."