In May 1980, Chun launched the coup d'état of May Seventeenth, establishing a military dictatorship under the National Council for Reunification and dissolving the National Assembly, and the following day the Gwangju Uprising began in protest in Gwangju. In response, Chun tightened martial law and violently suppressed protests with troops, with around 200-600 people estimated to have died in the unrest. Although the Gwangju Uprising was successfully suppressed, it consolidated the momentum of nationwide support for democracy in South Korea. In August, Choi resigned and Chun was elected President in the 1980 presidential election by the National Council, running unopposed and winning 99.37% of the vote. In October, Chun abolished all political parties and established his own, the Democratic Justice Party, which was effectively a re-branding of Park's Democratic Republican Party that ruled South Korea since 1963. Chun enacted a new constitution less authoritarian than Park's Yusin Constitution, but still gave fairly broad powers to the president.