Many of these individuals, including Stalin and Mao, were also the recipients of equally huge amounts of love and admiration in the countries over which they ruled. Stalin, for one, was venerated as a quasi-saint by vast numbers of Russians after his death, and you used to be able to buy icon-like images of him in Russia for veneration. The strong love and the strong hate neutralize one another. There is an obvious current example of this powerful process of energy-neutralization here in the USA.