Multiculturalism in the Netherlands began with major increases in immigration during the 1950s and 1960s. As a consequence, an official national policy of multiculturalism was adopted in the early 1980s. This policy subsequently gave way to more assimilationist policies in the 1990s and post-electoral surveys uniformly showed from 1994 onwards that a majority preferred that immigrants assimilated rather than retained the culture of their country of origin. Even though the general acceptance of immigrants increased, opinion polls from the early 1980s and after showed that many were critical of immigration. Following the murders of Pim Fortuyn (in 2002) and Theo van Gogh (in 2004) the political debate on the role of multiculturalism in the Netherlands reached new heights.