As discussed in Chap. 3, the literature on POS attributes great importance to the political culture and system of the receiving country regarding immigrant political incorporation. Eisinger’s (1973) point that the political participation depends not only on ‘group resources’ but also on how open and incorporative political institutions are emphasises the existing ‘barriers’ in the receiving country. These barriers are to some extent created by the institutional structure. Kriesi (1991) emphasises that the ‘formal institutional structure’ is important in terms of how institutional arrangements deal with those that challenge them and the political opportunities for those ‘challengers’. On the other hand, the fact that institutional opportunities are built on a political culture is stressed in many classics.