If we consider constitutional law as a practice, it is clear that both originalism and precedent play an important role. Neither one is going to vanquish the other, at least not any time soon. We can engage in academic debate about originalism versus stare decisis, as if they were rival modes of interpretation that could operate to the exclusion of the other. But the question of practical importance is one of degree and emphasis: in cases where these two sources of authority arguably point in different directions, which one should have a greater claim to our allegiance?
Originalism – interpreting the text in accordance with the understanding of the Framers – is arguably the more fundamental principle. Insofar as our legal system rests on legal positivism or the command theory of law – which it largely does, at least with respect to enacted law – then the Constitution must be regarded as the supreme command of the ultimate lawgiver, the People. When asking what command the People have given, it makes sense to ask what the People understood the provisions of the Constitution to mean at the time they were adopted. Thus, when questions of first impression arise, or disputes erupt about whether particular precedents should be overruled, nearly all Justices seem to regard evidence of original understanding as being relevant to resolving the issue.
Thomas W. Merrill,
Originalism, Stare Decisis and the Promotion of Judicial Restraint,
Available at: https://scholarship.law.columbia.edu/faculty_scholarship/354