A liar is someone who denies the truth to someone who has a right to it.
Those who gave misinformation to the Nazis to protect Anne Frank and her family, for example, were not liars: they were denying the truth to those who had no moral right to it. Candidates for the Supreme Court, on the other hand, are now routinely expected to be liars as they deny the truth about their intentions on issues where citizens have a moral right to be informed.
Solutions?