This article investigates idioms that conceptualize complex political issues in electoral discourse. The material consists of examples from British and American electoral debates and speeches (2010-2016) which show that politicians employ idioms for the purposes of self-presentation and their opponents’ criticism. Sharing a common language Americans and the British have different socio-political experience and culture, which manifests itself in idioms. The conceptual analysis of metaphors embedded in idioms reveals both common and culture specific features with regard to their manifestation in electoral discourses. The data show that the American discourse is characterized by the employment of metaphors that have mechanisms as their conceptual source and a very limited use of metaphors with the source domains Nature and Food. Moreover, the findings reveal that idioms used by British politicians are more diverse, thus more submodels are established within the source domains analyzed. Accordingly, British and American electoral discourses meet different stylistic requirements.  The next stage of analysis deals with idioms modifications. The investigation reveals that a significant number of idioms undergo transformations in electoral discourse. Politicians attempt to tailor them to a political context thus enhancing their imagery. The most common type is expansion, while contraction of idioms is quite rare.