Nativism informs the way in which far-right organizations identify the members of the national community and those who challenge or threaten it. According to a leading researcher on populist politics, Cas Mudde, nativism is an ideology that asserts «states should be inhabited exclusively by members of the native group (the nation) and that non-native elements (persons and/or ideas) represent a threat to the homogeneity of the nation-state» (Populist Radical Right Parties in Europe. Cambridge University Press). On the far right, differences between natives and non-natives tend to be justified mainly through racist and neo-racist nativist arguments stressing the distinct biological, cultural or civic characteristics of the national identity.