Democracy is a system in which parties lose elections. [Footnote:] Note that the presence of a party that wins elections does not define a system as … - Adam Przeworski

Capitalism is a system in which many scarce resources are owned privately, and decisions about allocating them are a private prerogative. Democracy is a system through which people as citizens may express preferences about allocating resources that they do not privately own. Hence the perennial question of political theory and of practical politics concerns the competence of these two systems with regard to each other. Is it possible for governments to control a capitalist economy? In particular, is it possible to steer the economy against the interests and preferences of those who control productive wealth?

The conclusions are self-evident, so I just state them. Electoral winners and losers obey the results of democratic competition and thus democracy is sustained merely as a consequence of political forces pursuing their interests. Whether this explanation is sufficient or some cultural patterns are necessary for democracy to endure is just hard to tell, as is whether democracy can survive even when it is not supported by economic self-interest.

Social democrats will not lead European societies into socialism. Even if workers would prefer to live under socialism, the process of transition must lead to a crisis before socialism could be organized.