Confidence converts to trust when exit or influence becomes available.

Evidence

If this is true, the relation between confidence and trust becomes a highly complex research issue. The question is not simply to assign expectations to types and to sort them according to whether they are based respectively on confidence or on trust. A relation of confidence may turn into one of trust if it becomes possible (or is seen to be possible) to avoid that relation. Thus elections may to some extent convert political confidence into political trust, at least if your party wins. Conversely, trust can revert to mere confidence when the opinion spreads that you cannot really influence political behaviour through the ballot. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 1383

Categorization

• XREF: Directly relevant to Saramago: the collapse of observability eliminates any possibility of exit or influence, forcing all expectations from trust back down to confidence or below.