Lots of villains in media tend to be both incredibly charismatic and highly manipulative. With their powers of persuasion, they can often amass a large following of people.
So, here is my question
How does a ruthless villain sway the public into thinking he is the true hero of the story, no matter how brutal he may be?
For example, the villain I am trying to write is essentially a brutal cult leader with a large following. Outwardly, he's a nice, empathetic person with a great smile and a heart of gold, but internally he's extremely cold, and the world is a den of violence because of him.
He does not hide the fact that he does horrible things. He is simply so charismatic that he makes otherwise good people follow him despite the horrible things he does.
What I want to know is how a villain could manipulate people so easily. Propaganda, brainwashing, and other means could do the trick, but I want to know how a villain could win over the public without even using underhanded methods, just using good old words and intelligence to get people on his side.