Oh, be quiet. So, so many voices right now are talking about a Supreme Court vacancy and whether it will be filled by a liberal or a conservative, a secular personality or a religious believer, a Democrat or a Republican, and all of that is beside the point.
The issue is judicial philosophy, whether the nominee thinks the job is about interpreting the actual words of the Constitution correctly or someone who thinks it is maybe about making some reference to the Constitution but chiefly applying his or her own notions of what the actual principle should be, his or her compassion, his or her moral and societal aspirations, his or her politics. No, we do not want moral cynics making these decisions, but what’s wrong is to resort to self instead of what is spelled out on paper.
Focusing on a reasonable evaluation of the literal intent of the document, what the words mean, what history tells us about arguments of that moment, is called rule of law. Different interpretations are plausible, there are precedents to consider and each case before the court is likely to have its own peculiarities. But the objective should be to understand and apply what the Constitution actually says.
It is Congress and state legislatures that are supposed to write the laws, not the court, which should aim at seeing whether they adhere to the Constitution. It is also all kinds of other officials who make all kinds of decisions that the court may also check out through what the Constitution or other laws actually say. When the court steps in without serious reference to the law, there goes the separation of powers, there goes the republic, there goes the consent of the people. Authoritarianism scoots closer.