I'm thinking of Milton Friedman, recently deceased at the age of 94. Friedman was a bad guy who had a bad influence on the world. Ideologically, the guy was a complete nutbar. A libertarian, he opposed all forms of government "interference". He opposed taxation, public education, driver's licenses, the minimum wage and unions. He thought the regulation of doctors caused unnecessarily high medical costs and should be abolished. And so on and so on.
Friedman's great legacy was in shaping the economic policies of Margaret Thatcher, Ronald Reagan and Augusto Pinochet. Some legacy. He was also a public propagandist. His influence was in the encouragement of prosperity at all costs without concern for the effect on individuals. And what did it all come down to? - Tax cuts for the rich, more income disparity, more pollution, a smaller social safety net, higher crime, a meaner world.
I'm not arguing that the guy wasn't smart, or that he wasn't a good economist. He was a frickin' genius. So, probably, was Hitler. Had Hitler waited a few more years before invading Poland, maybe the Nobel committee would have given him a prize.