The Christian Democratic Appeal (CDA) is a Christian democratic political party in the Netherlands which was founded on 23 June 1973 as an alliance of the Catholic People's Party, the Anti-Revolutionary Party, and the Christian Historical Union. Rising secularism in the Netherlands during the 1960s led to the Christian democratic parties declining, causing the left wing of the Christian democratic movement to form the Political Party of Radicals, and the remaining centrists and conservatives to align behind the Christian Democratic Appeal alliance. The three parties ran under the same banner in the 1977 election and formally united into one party on 11 October 1980. Over time, the CDA became a major coalition partner, participating in all but three governments (as of 2021) since its formation. The party's commitment to Christian values was tempered, as the CDA also had Jewish, Muslim, and Hindu members of parliament, and it was more committed to stewardship, solidarity, shared responsibility, and public justice. The party also supported the cooperation of the state, the market, and all social institutions (such as churches and unions). In 2012, the CDA adopted a new, centrist course which supported a flat tax, eco-friendly policies, a pro-European Union policy, a more friendly immigration policy, equal chances for every person, more investment in higher education, and a modern social policy. In 2017, the CDA won 12.4% of the vote.