Half truths contain elements of reality that complicate refutation. That’s why a half truth is worse than a lie. In addition, the art of the half truth is a longstanding technique of political rhetoric.
Perhaps the most recognizable form of this is when government officials suggest that, if they don’t get what they want, there will be dire consequences. The classic example is when local officials want voters to pass revenue enhancements, such as tax hikes or bond proposals.