Has there been a root cause analysis on why the racists and misogynists only strike sometimes? They appeared to be powerless when the Democrats nominate charism

Has there been a root cause analysis on why the racists and misogynists only strike sometimes? They appeared to be powerless when the Democrats nominate charismatic candidates like Obama. My read from a distance is the man was propelled somewhat by his racial background. I put it - as an outside chance - that it is possible that the policies and outcomes of said policies have a bearing on the voting decisions people make.