Candidate selection is a major function exercised by political parties. Yet they differ significantly regarding who selects their candidates. This article intends to launch an exploration beyond “the secret garden of politics,” classifying party selectorates along both dimensions of inclusiveness and centralization. Regarding the large differences across parties, one can wonder whether these variations in the candidate selection modes have an impact on the type of candidates selected. The article empirically tests the relationship between candidate selection modes and the degree of mass–elite ideological congruence, using positions of candidates and voters on the left–right scale and on an issue related to the authoritarian–libertarian scale. Ten Belgian political parties are analyzed, for two federal elections – a regular (2007) and an early election (2010). The urgent context of the 2010 elections forced some parties to render more exclusive their selection mode. Variations across cases are thus further amplified. Our results confirm that the selection mode is linked to the degree of congruence. More exclusive selectorates tend to select candidates being ideologically closer to their voters. This could be explained by stronger connections between party leaders and the party electorate, and by more exclusive selectorates being more pragmatically seeking votes.