revolutionaries. The Constitutionalist faction won the revolution and its leader, Venustiano Carranza, had a new constitution drawn up, the Constitution of 1917. It strengthened the anticlerical provisions of the previous document, but President Carranza and his successor, General Alvaro Obregón, were preoccupied by their struggles with their internal enemies and as a result, they were lenient in their enforcement of the Constitution's anticlerical articles, especially in areas where the Church was powerful. The administration of Plutarco Elías Calles believed that the Church was challenging its revolutionary initiatives and legal basis. To confront the Church's influence, anticlerical laws were instituted, which triggered a ten-year-long religious conflict in which thousands of armed civilians were killed by the Mexican Army. Some have characterized Calles as the leader of an atheist state and his program as being one to eradicate religion in Mexico. 1917 Mexican Constitution The 1917 Constitution was drafted by the Constituent Congress convoked by Venustiano Carranza in September 1916, and it was approved on February 5, 1917. The new constitution was based in the 1857 Constitution, which had been instituted by Benito Juárez. Articles 3, 27, and 130 of the 1917 Constitution contained secularizing sections that restricted the power and the influence of the Catholic Church. The first two sections of Article 3 stated: "I. According to the religious liberties established under article 24, educational services shall be secular and, therefore, free of any religious orientation. II. The educational services shall be based on scientific progress and shall fight against ignorance, ignorance's effects, servitudes, fanaticism and prejudice." The second section of Article 27 stated: "All religious associations organized according to article 130 and its derived legislation, shall be authorized to acquire, possess or manage just the necessary assets to achieve their objectives." The first paragraph of Article 130 stated: "The rules established at this article are guided by the historical principle according to which the State and the churches are separated entities from each other. Churches and religious congregations shall be organized under the law." The Constitution also provided for obligatory state registration of all churches and religious congregations and placed a series of restrictions on priests and ministers of all religions, who were not allowed to hold public office, canvas on behalf of political parties or candidates, or inherit from persons other than close blood relatives. It also allowed the state to regulate the number of priests in each region