Augustus Caesar was one of the most successful with the technique. Unlike the less deferential Julius Caesar, he carefully paid respect to the Roman Senate while systematically stripping it of authority.
He knew a simple truth: In the eyes of many people, if you provide the trappings of belief, you need not provide the substance, for they will find it difficult to conceive that anyone can be so hypocritical and, under some circumstances, the illusion will be more important to them than the reality.
Dictators have long mastered the practice. Stalin joked with audiences of party leaders who were already slated for the Gulag or worse. The Nazis put "Work Will Make You Free" over the entrances of their death camps and had musicians play Mozart while people were marched to the gas chambers. The idea was to permit just enough hope so those fervently searching for it could find a basis to justify their belief.
Some of the greatest scoundrels I've ever met were quite personable. They had all of the trappings of a normal, civilized person, but if you ignored their soothing words and looked at their record, you would find a very different picture. At some point, they had learned that a winning smile and vows of sensitivity will cause others not simply to drop their defenses, but to suspend judgment even in the presence of one damning bit of evidence after another. Like the greatest of magicians, they could make their victims devoutly determined to see something that did not exist.