What Is The Role of Artists In Promoting Dictatorships Through History?

Through history the artists were used to popularize tyrants among their people. Stalin had his portraits and pictures every where in his country. So was Hitler pictures and paintings every where in Germany. So those of Mao Tze Tong in China, Hussein in Iraq and Kemal Ata-Turk-Pot in Turkey to the very present day and moment. So are the artists guilty in this respect?