These kinds of tools always been used by those who advocate & benefit from state sponsored terror of its citizens. It was as probably true 10,000 years ago as the first proto-states developed as it is today.
So, while the constant threat to individual freedom & liberty isn't new, the ways & means that it's engineered can alter from case to case.
IMO, however, what's really remarkable aren't the tricks & games used to achieve divide & conquer, but that the people of the US finally woke up in time to recognize the threat.
I'm not convinced. The coalition of leftist politics, interest groups, government, main-stream media and some crony capitalists have convinced a good part of the USA population that the multi-culti, PC nonsense is a new, sacred religion.