Under what conditions are mass attitudes towards particular issues ‘vertically’ constrained by core cultural values? Vertical constraint is shaped by three related variables: the objective content of the issue, the way the issue is framed by elites and the individual's level of attentiveness to the controversy. Some issues are ‘easy’. They so permeate social discourse that people encounter, often without wanting to, many social agents offering shortcuts for the vertical, values-to-issue link. Most issues, however, are ‘hard’. Arcane in content and bereft of vigorous mediation, hard issues are more difficult for individuals to tie to core values. As the inferential connection between value and issue lengthens, and as social agents become fewer and more remote, an individual's ability to use values to interpret issues will increasingly depend on whether the decision makers, activists and other elites directly involved in the debate can create a connection and, of course, on whether the individual is paying attention. An analysis of the nuclear power controversy, a highly complex technical issue, reveals that a value-based interpretation favoured by elites and promoted by the media is faithfully reflected in how the mass public understands the issue. Furthermore, non-elites who are more attuned to political life are more polarized on the basis of these core values.