By 1960, Rhee had already served three terms in office. His next victory was certain after the main opposition candidate, Cho Byeong-ok, died shortly before the March 15 elections. Rhee won with 90% of the vote. The real contest was in the race for vice president. This was held separately under the law of the time. Yi Gi-bung, who Rhee thought should take over after him, was declared the winner of an election that the opposition claimed was rigged. This created anger among groups of the Korean people. A student-led April 19 Movement forced Rhee to resign on April 26. 