Plural form; potentially refers to people who support constitutionalism, or constitutional principles/documents (archaic usage).
The plural of 'constitutional,' which can function as a noun meaning either 'a person' (in historical usage) or 'constitutional principles.' This usage is quite rare in modern English.
In 18th-century writings, you might see 'constitutionals' used to describe supporters of constitutional government—it's a quirky historical term that shows how words change when political ideas evolve!
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