  Metaphors are widely used in political rhetoric as an effective framing
device. While the efficacy of specific metaphors such as the war metaphor in
political discourse has been documented before, those studies often rely on
small number of hand-coded instances of metaphor use. Larger-scale
topic-agnostic studies are required to establish the general persuasiveness of
metaphors as a device, and to shed light on the broader patterns that guide
their persuasiveness. In this paper, we present a large-scale data-driven study
of metaphors used in political discourse. We conduct this study on a publicly
available dataset of over 85K posts made by 412 US politicians in their
Facebook public pages, up until Feb 2017. Our contributions are threefold: we
show evidence that metaphor use correlates with ideological leanings in complex
ways that depend on concurrent political events such as winning or losing
elections; we show that posts with metaphors elicit more engagement from their
audience overall even after controlling for various socio-political factors
such as gender and political party affiliation; and finally, we demonstrate
that metaphoricity is indeed the reason for increased engagement of posts,
through a fine-grained linguistic analysis of metaphorical vs. literal usages
of 513 words across 70K posts.
