In modern liberal democratic societies, freedom of speech is one of the fundamental rights of an individual guaranteed by the constitution. It is also the foundation of a democratic state. This right is sometimes abused for political purposes and demagogic propaganda, in both totalitarian systems and democracies, which adversely affects the stability of a state. Propaganda mechanisms negatively influence the sphere of community values and concepts which change their meanings through manipulation. The author examines the language of demagogic propaganda and concludes that it disrupts the communication process in society. These destructive tendencies are opposed under the political culture of a democratic society, thanks to legal regulations protecting freedom from manipulation.