Most mixed regimes are hybrids, but only some hybrids warrant a separate type label.

Evidence

If we think of parliamentary and presidential government as Weberian ideal types, we must acknowledge that there are numerous regimes that contain some elements of one and some elements of the other, and are thus hybrids. However, not all combinations of these elements qualify a regime as “semipresidential,” unless that term is nothing more than a synonym for “hybrid.” — Gary Goertz, Social Science Concepts and Measurement, 1056

Categorization

• SHARE: A tidbit for someone working on comparative constitutional design — the quip that ‘semipresidential’ may just be a synonym for ‘hybrid’ is worth sending.
• XREF: Echoes the earlier framing of ideal types as poles of a concept pair; the hybrid sits between poles without automatically earning its own category.