The young man, with a bent toward eliminating the 'menace' of a group previously held as slaves in his state, clearly adhered to the ideas of that time.
His cause is, thus, not dead.
There may be much more to this.
Roof ??????
If you're talking about the young man that killed the nine people attending church, it was an individual that was filled with anger, hatred, confusion, no direction in life, obvious self-esteem issues, is mentally unstable, and wanted to take all of it out on an easy target. Society is filled with such individuals. We have many people that would fit all of the above mentioned problems. We have many people that could go postal at any given moment. We have problems in this country that go beyond racism, group identity and affiliation, and inbred hatred. Our social and economic woes are fueling an escalation in violence and inhumane actions.
Although it's easy to blame guns, guns are only a means to express the anger and frustrations felt by many. Guns are nothing more than tools used to carry out hatred and anger. If guns weren't available, we'd see homemade bombs, deadly chemicals, deadly biological weapons, and other items used to kill. People that are mentally unstable, angry, filled with hate, racist, and those with no purpose or direction in life, will find a way to vent, and to carry out inhumane acts of violence.
At this time, I see no way of detecting these individuals before they explode. Many of them remain silent and passive until they reach a breaking point. It would be very difficult to detect these people since no one can read minds. In many cases, in my opinion, social and economic pressures are partially to blame, and certainly fueling the flames. I don't have all of the answers, but I do know that given present social and economic conditions, the worst is yet to come. Many people have just plain given up, can see no future, and are at or very close to their breaking point.
Racism, in my opinion, adds fuel to the already burning fires of frustration, anger, the sense of desperation, the absence of a bright future, and lost hope for the immediate individual's crisis.