In May 1967, Park was re-elected President in the 1967 presidential election, defeating Posun of the New Democratic Party with 51.4% of the vote. The South Korean constitution limited the President to two four-year terms, meaning Park was not eligible to run for re-election in 1971 upon the end of his term. However, in 1969 the Democratic Republican Party-dominated National Assembly forced through a constitutional amendment to allow him to seek a third term. Park ran in the May 1971 presidential election and defeated his New Democratic Party opponent Kim Dae-jung with 53.2% of the vote.