President Arturo Alessandri Palma (1920-24, March-October 1925, 1932-38) appealed to those who believed the social question should be addressed, to those worried by the decline in nitrate exports during World War I, and to those weary of presidents dominated by Congress. Promising "evolution to avoid revolution," he pioneered a new campaign style of appealing directly to the masses with florid oratory and charisma. After winning a seat in the Senate representing the mining north in 1915, he earned the sobriquet "Lion of Tarapacá." As a dissident Liberal running for the presidency, Alessandri attracted support from the more reformist Radicals and Democrats and formed the so-called Liberal Alliance. He received strong backing from the middle and working classes as well as from the provincial elites. Students and intellectuals also rallied to his banner. At the same time, he reassured the landowners that social reforms would be limited to the cities....

As the candidate of the Liberal Alliance coalition, Alessandri barely won the presidency in 1920 in what was dubbed "the revolt of the electorate." Chilean historians consider the 1920 vote a benchmark or watershed election, along with the contests of 1938, 1970, and 1988. Like other reformers elected president in the twentieth century--Pedro Aguirre Cerda (1938-41), Gabriel González Videla (1946-52), and Salvador Allende Gossens (1970-73)-- Alessandri had to navigate skillfully through treacherous waters from the day he was elected until his inauguration, warding off attempts to deny him the fruits of victory. Mass street demonstrations by his middle- and working-class supporters convinced the conservative political elite in Congress to ratify his narrow win.

After donning the presidential sash, Alessandri discovered that his efforts to lead would be blocked by the conservative Congress. Like Balmaceda, he infuriated the legislators by going over their heads to appeal to the voters in the congressional elections of 1924. His reform legislation was finally rammed through Congress under pressure from younger military officers, who were sick of the neglect of the armed forces, political infighting, social unrest, and galloping inflation.

In a double coup, first military right-wingers opposing Alessandri seized power in September 1924, and then reformers in favor of the ousted president took charge in January 1925. The latter group was led by two colonels, Carlos Ibáñez del Campo and Marmaduke Grove Vallejo. They returned Alessandri to the presidency that March and enacted his promised reforms by decree. Many of these reforms were encapsulated in the new constitution of 1925, which was ratified in a plebiscite.