Some bristle at the idea of a “living Constitution,” rejecting anything that isn’t expressly written in the text. I understand disagreeing with the concept that we have this amendable document that nonetheless we can just make up as we go along. That, however, is a shallow understanding of what the document says and what is actually going on. The text does matter, and it’s extremely rare for anybody to just make something up (and even that can be changed). There are roughly two kinds of Constitutional provisions – the objective, and the subjective. Objective provisions are those such as the President being 35 years old, or the Senate is composed of two Senators from every state. No interpretation or special understanding is needed.
Subjective provisions are those like “due process,” “unreasonable search and seizure,” “cruel and unusual punishment.” These vitally important parts of the Bill of Rights are necessarily vague. Does this mean we just make up what the words mean every time we apply them? Of course not. But it does mean that interpretation is needed. So what do we do? We use a combination of precedent (what we did before), and pragmatism (what makes sense now) influenced by legislative intent (what was the point in the first place). Precedent should and does take an outsize role, but it’s not absolute, as the forward-thinking men who wrote these important but undefined phrases would expect their descendants to learn from the past and chart their own path forward, within their existing framework. Which, of course, is largely what we’ve done. How else can we apply legal concepts from the Enlightenment to the technological and social questions of today, some topics that would be indistinguishable from magic to the Founders.