PARTIES AND IDEOLOGY
As we saw in the Introduction, parties have frequently been understood as vehicles that bring together those of similar political opinions. Especially in liberal democracies, parties are popularly perceived as differing from one another in respect of the views and ideologies they espouse. Parties are seen as arenas in which opinions about public affairs are organized: each party in a particular party system has its own ideas and approach to the relation between state and society and to the role of the state. Nor is this popular view, that parties do have different ideologies, a misplaced one. As Klaus von Beyme says of Europe, 'Over the longer term only parties based on an ideology have succeeded in establishing themselves.' 1 Thus, it is not surprising that a comparative study of political parties should begin by considering parties as organizations that have, or purport to have, an ideology.
Of course, the ideological 'dimension' of parties must be placed in context. An obvious point to make is that, even in Europe, during the period of transformation to liberal democracy (in the late nineteenth and early twentieth centuries) there were many parties whose sole raison d'être was obtaining patronage through their control of political offices. The demands imposed by having to compete for the votes of a mass electorate may have entailed the embracing of an ideology, but the non-ideological aspects of politics continued to infect many parties well into the twentieth century. But, while we must not lose sight of this point, the centrality of ideology in party politics is undeniable. But how should political scientists try to understand the adoption of a particular ideology and, more especially, the persistence of that ideology or its modification?