From 1903 until 1968, Panama was a constitutional democracy dominated by a commercially oriented oligarchy. During the 1950s, the Panamanian military began to challenge the oligarchy's political hegemony. In October 1968, Dr. Arnulfo Arias Madrid, twice elected president and twice ousted by the Panamanian military, was ousted for a third time as president by the National Guard after only 10 days in office. A military government was established, and the commander of the National Guard, Brigadier General Omar Torrijos, soon emerged as the principal power in Panamanian political life. Torrijos' regime was harsh and corrupt, but his charisma, populist domestic programs, and nationalist (anti-U.S.) foreign policy appealed to the rural and urban constituencies largely ignored by the oligarchy.