I did not say sincerity is not a virtue, I said it is overrated. I don't think Santorum is even close to being Hitler, I believe he is overall an honest man who believes that he will do good for the country. My problem with him is that he is so certain with his beliefs. He's too dogmatic for my taste. “The most harm of all is done when power is in the hands of people who are absolutely persuaded of the purity of their intentions” – Milton Friedman

Being sincere doesn't mean to always tell the truth. Lies can be justified as a means to achieve a goal that is sincerely believed to be for the greater good.

That's what makes these people dangerous. If they had an obsession with telling the truth, they would be easy to defeat, because even though many people share some of their beliefs, very few people share the priorities of true fanatics.

Yeah you're right. I don't think Hitler was sincere when he negotiated with Neville Chamberlain on the annexation of the Sudetenland in Czechoslovakia. No one was listening to Churchill who has been warning for years about Hitler. Who would listen to a drunk discredited politician? This time pragmatism failed.