Lowercase the adjective form

Style note²Federal courts, Illinois courts21st and 22nd editions

Congress, the President and the Constitution take capitals as nouns; the adjectives formed from them stay lowercase, as in “his constitutional rights”, unless part of a proper name.¹

1. 1R. 8(d)(ii) Exceptions; R. 8(c)(ii) Exceptions; R. 8(d)(i) Nouns that identify specific persons, officials, groups, government offices, or government bodies; R. 8(c)(i) Nouns that identify specific persons, officials, groups, government offices, or government bodies.
2. 2A style note: the rule in note 1 allows both forms and prefers one.