There is only one proper way to faithfully interpret the Constitution. And that is to ascertain the actual meaning of the words of the text, taken in their proper social and linguistic context.
That meaning must be the objective meaning — not the reader’s subjective understanding or preferred reading. And that meaning must be the original meaning — that is, the meaning the Constitution’s words and phrases would have had to reasonably informed readers of the English language at the time they were used, in context, and accounting for any specialized usages or term-of-art phrases. Any other reading is pure anachronism, a misuse of language.
This single correct method of constitutional interpretation travels under many names. I call it “original-public-meaning textualism,” emphasizing the text and the requirement that it be taken in its known, original sense. A convenient (if imprecise) shorthand term is simply “Originalism.” It contrasts, sharply, with any of a variety of progressive theories under which the Constitution’s meaning shifts, morphs, evolves, or otherwise transmogrifies to suit the needs or circumstances of the moment — and, typically, to serve the interpreter’s desired political agenda.
There are many good arguments in favor of Originalism: It is less subject to manipulation, produces greater clarity and consistency, better preserves democratic decision-making, and frequently yields better results than any other method. All of these points are true and important.