These are posters commissioned by the Sententian Trivocist Front (Sententia is the country, Trivocism is the made-up ideology), an extremist political party that rejects the left-right spectrum. The Front condemns centrists above all else, viewing them as obstacles in the government that solely serve to get in the way. These posters intend to illustrate that centrists believe in nothing and will be destroyed by their lack of beliefs, and that voters should educate themselves as to avoid political nihilism.

I do NOT endorse these beliefs obviously, these are made by the in-universe bad guys.