Over the years, three different approaches have been developed for grounding originalism.
1. The first approach involves a normative argument for originalism. Under this approach, one argues that originalism is the normatively best way to interpret the Constitution. There are various versions of this approach. Justice Scalia argues that only originalism leads to clear rules to guide judges and the public. Judge Bork contended that originalism is the only approach compatible with democracy. Keith Whittington maintains that originalism is justified by popular sovereignty.
2. The second approach is an interpretive argument for originalism. Under this approach, one argues that the actual meaning of the document that is the Constitution is the original meaning. To determine the actual meaning, one must give it the meaning it would have had at the time of its enactment. This approach is adopted by both original public meaning advocates, such as Gary Lawson, and original intent defenders, such as Larry Alexander.
My own approach (with John McGinnis) makes both kinds of arguments. We argue originalism is the normatively best way of interpreting a good constitution and there is a strong reason to believe that a constitution enacted pursuant to strict supermajority rules will be a good one. We also argue the actual meaning is best determined through original methods originalism, which interprets the meaning of the Constitution based on the interpretive rules that would have been deemed applicable to the Constitution at the time of its enactment.
3. But there is a third approach to originalism: this involves what the law is today. Under this approach, one would argue that originalism is what the law is today. That is, the most accurate reading of the law today requires originalism.
This approach, I think, is a harder one than the others. After all, one might argue that, of course, originalism is not the law today. The Supreme Court regularly decides cases that do not conform to originalism and it often does so employing interpretive methodologies that are not originalist.
Yet, the matter is a more complicated than that. While the Supreme Court decides cases from a nonoriginalist perspective, the justices have almost never said that they are contravening the original meaning of the Constitution, except where precedent requires (or allows) them to do so.
In the past, I have not really explored this third approach very much for a variety of reasons, including my skepticism about theories of law. But I have become more interested in it lately. And so I plan in the next couple of weeks to do a couple of posts on the issue.
My next post: A Dworkinian argument for originalism.