Justice Thomas's majority opinion in Bruen provides a roadmap of how to use originalism based on analogical reasoning--that is, how to look at practices from prior to ratification of the Second Amendment. The Court also discusses, at some length, how to consider post-enactment practice. This issue has been subject to debate in originalist circles for some time. In Heller, for example, Justice Scalia considered gun restrictions that were enforced following the ratification of the Second Amendment. Justice Stevens criticized Scalia with a charge of hypocrisy: why would an originalist look at history that came after the Second Amendment's adoption? Scalia replied that originalists can rely on post-ratification history that confirms pre-ratification history. That confirmation suggests a continuity, in which the meaning of the text did not change over time. By contrast, post-ratification history is less useful if there was no continuity--that is, there was some later-in-time break in practice that suggested a shift in meaning.
In Noel Canning, Justices Breyer and Scalia disagreed about this point. Breyer suggested that post-ratification practice could potentially trump original meaning--at least where the text was ambiguous. Scalia, by contrast, rejected this "adverse possession" approach to constitutional law, in which the executive branch can aggrandize its power by violating the Constitution for long periods of time.
This debate has continued to simmer. Thankfully, Justice Thomas brought some clarity to the issue in Bruen.
