Ketuanan Melayu is the racialist belief that the Malay people are the "tuan" (masters) of Malaysia or Malaya; Malaysian Chinese and Indian Malaysians are considered beholden to the Malays, who have granted them citizenship in return for the Malays' special privileges as set out in Article 153 of the Constitution of Malaysia. This quid pro quo arrangement is usually referred to as the social contract, not to be confused with the usual idea of a social contract between the government and the people. The most vocal opposition towards the concept has come from non-Malay-based parties, such as the Democratic Action Party. However, the portions of the Constitution related to ketuanan Melayu were "entrenched" after the racial riots of May 13 1969, which followed an election campaign focused on the issue of non-Malay rights. The riots caused a major change in the government's approach to racial issues, and led to the introduction of an aggressive affirmative action policy strongly favouring the Malays, the New Economic Policy. The National Culture Policy, also introduced in 1970, emphasised an assimilation of the non-Malays into the Malay ethnic group. However, during the 1990s Prime Minister Mahathir Mohamad rejected this approach, with his Bangsa Malaysia policy emphasising a Malaysian instead of Malay identity for the state.