It is more complicated than Left vs Right (as the Goldman suggests) since there are similar signs on both side, I think he is fundamentally correct when he writes that

Emil Durkheim’s 1897 diagnosis of “anomic suicide” describes the Columbine perpetrators as well as the 2016 San Bernardino attack by Muslim fanatics, the “right-wing” shooter in El Paso and the “left-wing” shooter in Dayton. They are individuals cut off from society, destabilized by change and despairing of their own place in the world. Such monsters always have been among us. But now we are cultivating such monsters by destroying the ties that bind us to each other, to our past and to our future.”