This thesis analyses how the institutional context of democracies shapes the way citizens evaluate, and what they do ideally expect, from their democratic systems. Although there is a long tradition in political science studying the institutional causes of democratic attitudes, the literature has been commonly focused on the effects of a small group of institutions on a set of attitudes that tap very ambiguously what the citizens actually feel about their system. From the side of institutions, these have been mainly identified with institutions of political representation—notably, electoral and party systems—while other formal arrangements equally relevant for the citizens, such as the rule of law or the welfare state, have remained fairly overlooked. As for popular attitudes toward democracy, the traditional indicators have sought to tap into individuals’ overall assessments of the system but have not allowed scholars to distinguish between the diverse elements with which citizens may be differently satisfied, or to identify their ideal aspirations about the system. By drawing on an innovative dataset that measures individuals’ democratic aspirations and evaluations in a nuanced way, as well as on a large range of macrolevel data on the performance of democracy, the thesis provides a comprehensive framework to understand how political institutions affect citizens’ aspirations and evaluations of democracy in European countries. The thesis starts by discussing the extent to which the new empirical concepts of aspirations and evaluations are indeed sound and meaningful and can serve to elaborate a fine-grained theory on public attitudinal beliefs about the democratic system. Next, I sketch out the theoretical framework of the thesis, which develops around the multifaceted connections between institutions and democratic aspirations and evaluations within specific dimensions of democracy. The results of the three empirical studies provide positive support for the two main hypothesized effects of the framework: (i) Aspirations work as a cognitive yardstick for how citizens evaluate institutional performance; and (ii) Institutions activate the effect of aspirations on performance evaluations by connecting what citizens expect from their democratic system to what they actually gain. This approach covers thus a gap in the literature on public opinion by acknowledging the socio-psychological process underlying the formation of public attitudes toward democracy. In the conclusions, the thesis discusses how these findings qualify much of what we know about the causes and implications of different degrees of public attachment to democracy, and draws insights into the institutional designs that really contribute to build people’s positive attitudes toward democracy.