In 1951, Joseph S. Clark was elected as the first Democratic mayor in 80 years. Clark filled administration positions based on merit and worked to weed out corruption. Despite reforms and the Clark administration, a powerful Democratic patronage organization eventually replaced the old Republican one. Clark was succeeded by Richardson Dilworth, who continued the policies of his predecessor. Dilworth resigned to run for governor in 1962, and city council president James H. J. Tate was elected as the city's first Irish Catholic mayor. Tate was elected mayor in 1963 and reelected in 1967 despite opposition from reformers who opposed him as an organization insider.