The most obvious deviation from the ideal of "one nation, one state" is the presence of minorities, especially ethnic minorities, which are clearly not members of the majority nation. An ethnic nationalist definition of a nation is necessarily exclusive: ethnic nations typically do not have open membership. In most cases, there is a clear idea that surrounding nations are different, and that includes members of those nations who live on the "wrong side" of the border. Historical examples of groups who have been specifically singled out as "outsiders" are the Roma and Jews in Europe.