I’ve just come across this quotation of Maurice Saatchi which I thought was both very insightful and, appropriately, beautifully put:
“Posters are to politics what poetry is to literature. The only possible words in the only possible order.”
Maurice (now Baron) Saatchi founded advertising agency Saatchi & Saatch and oversaw the production of the vast majority of the most memorable pieces of political advertising in British history.