Petkovich was born in Arvada, DCD, to a Croatian Rioblancoan father, Bogdan "Danny" Petković, whose family fled Croatia and settled in Rio Blanco to avoid the war, and to a Rioblancoan mother, Sally Gynsburgh. According to his father, he was named after John Wayne. Unlike some other prominent politicians, Petkovich entered politics well in his twenties, without any experience. After his term as Senator expired, he was appointed Chancellor by President Bill Stanmourne.