This case study points out the ways in which multimodal texture contributes to the dominant persuasive function of political advertising discourse. It is based on a dataset of 27 televised advertisements by the Democratic presidential candidate Bernie Sanders, aired during the primary election period between October 2019 and March 2020. A qualitative approach is adopted, combining methods of political discourse analysis and multimodal approaches to cohesion. As an investigation of conjunctive relations between words and images shows, the three dominant modes in this type of mediatized political discourse serve complementary and mutually reinforcing functions: the spoken words in the advertisements typically constitute the central cohesive chain, while written captions on the screen highlight selected political keywords and slogans, and the visual images illustrate and exemplify the line of arguments. On this basis, it is shown that multimodal cohesion supports the three pivotal persuasive strategies of foregrounding the candidate, propagating the political agenda, and polarizing public opinion.