I might seem like a legal nihilist based on some of my tweets, but I’m not really.
The law does mean something–there are some legal results the text compels, and others it forbids. It is possible to be right or wrong about it.
At times, the Supreme Court gets it wrong, which means that we all have to go along with a wrong reading of the law in courts. These wrong interpretations don’t stop being wrong. For instance, most of the Supreme Court’s recent Second Amendment jurisprudence is wrong, but it’s the “law” in the sense that the Supreme Court says it’s the law, not because it’s a faithful or even good faith interpretation of the Constitution. This is Wrong Law.
However, for most interesting legal questions, there is no clear answer. The words are ambiguous and have to be given substance by various ad hoc theories, or by policy arguments or political ideology. Sometimes statutes are ambiguous because it’s deliberate. Other times, it’s the only text that could get enough votes, and no one likes it. Other times, it’s just the nature of language itself. People usually pick the legal theory that produces the results they want. (“Originalism” is perhaps the least helpful one, because what if the original intent was to use broad, somewhat meaningless terms with the expectation that they would be interpreted in different ways by different people over time? Which is what actually happens. Also legislative bodies don’t have an “intent” and the person who wrote a bill doesn’t have any special say in what it means over other legislators who voted for it in any event.)
In these cases, the ambiguities of language mean that “the law” really, actually is whatever the courts (or administrative agencies) say it is, because the legislature has in effect delegated the duty of deciding what the law is through its use of ambiguous words or even through express delegation. In these instances, which are common, there are good and bad “interpretations” of the law in the same sense that there are good and bad statutes, but these are political and policy arguments, not “legal” ones. Also, sometimes the universe of outcomes has been constrained by use of the right words, and judges and administrative agencies may have procedural hurdles to deal with that legislatures don’t. But with all of those caveats, judges (and administrative officials) are political actors and it’s their job to put forward “interpretations” of the law that suit their political or ideological interests.
However, judges only have the legitimacy to do that if they know when not to do it, that is, in the cases where the law really is clear as to particular results. The smart ones realize this. A judiciary that is obviously lawless in the sense of being unconstrained by the actual texts it is supposed to be interpreting will just end up being ignored by the executive branch (who have police, the military, and jails) and the legislature (who write the laws, and who set the budget). The judiciary is only strong in the theoretical sense that the Supreme Court can put forward any old crap in a judicial opinion, and there is no appeal, but it is weak in the sense that it requires people to voluntarily go along with its pronouncements. It has authority, not power. It is thus in the interest of the judiciary to use its ability to define the law with caution, because failing to do so is an abdication of authority.
ps: This is just my take on the system that actually exists. There may be better ones. I’m pretty sure there are.