Constitutional theory features a persistent controversy over the source or sources of constitutional status, that is, over the criteria that qualify some rules as constitutional rules. This Article contends that no single criterion characterizes all of the rules that American law treats as constitutional, such that it is a mistake to think of constitutionality as a status with necessary conditions. It is better to think of constitutionality on a bundle-of-sticks model: different attributes associated with constitutionality might or might not be present in any constitutional rule. Analysts should often direct their attention more to the separate substantive properties that are associated with constitutionality than to the question of constitutional status itself.
Primus, Richard A. "Unbundling Constitutionality." U. Chi. L. Rev. 80, no. 3 (2013): 1079-153.