There is always a secret relief — even, I imagine, among his supporters — when President Trump does not do something random and imprudent. And we can be thankful for the selection of a Supreme Court nominee that did not involve a Ouija board spelling out the name of a Fox News personality.

But this is one area in which even the chaos president is tightly constrained. A favorable Supreme Court is the single, nonnegotiable condition that social conservatives have placed on their support. The president has said he could “stand in the middle of Fifth Avenue and shoot somebody” and not “lose any voters.” But if he stood in the street while appointing somebody such as David Souter, he would swiftly become political roadkill.

The focus on Supreme Court nominations is related to a key moment in the conservative narrative. The story is this: During the 1987 battle over the nomination of Robert H. Bork to the Supreme Court, Democrats threw out the rule book of decency, honesty and fairness, smearing and defeating a conservative hero. The result was President Ronald Reagan’s choice of Anthony M. Kennedy, the swing vote who upheld abortion rights. The moral? To get nominees who respect the highest constitutional principles, Republicans must be prepared to practice the lowest type of politics.

Democrats have their own thick catalogue of complaints — now featuring the shabby treatment of Merrick Garland — that they think justifies anger and ruthlessness. But the main reason Supreme Court nomination battles are such spectacles of bitterness is the role that the court has assumed in our public life. What Alexander Hamilton called “the least dangerous” and “weakest” branch of government has become the main stage of the culture war, dealing with sexual preferences, family makeup and the value we place on life. In many cases, the legislative branch

This is a large part of what provoked and distorted the return of religious conservatives to politics — a reaction to the aggression of liberal courts. Conservative Christians became politically active — a good thing — but too reactive and overly focused on sexual matters. It has left them without a comprehensive vision of human dignity and vulnerable to the single-issue appeal of political con men. It is neither thoughtful nor faithful to associate Christianity with a leader’s racism, sexism and cruelty as long as he chooses judges from the Federalist Society list.

But the culture-war context of Supreme Court nominations has also distorted a serious discussion of constitutional interpretation. Conservative thinkers generally advocate originalism and judicial restraint. We have a written Constitution for a reason: to tie our political practice to an impartial text. We make the interpreters of the Constitution subject to the words of the Constitution. And the principle of self-government requires judicial deference to democratic choices, except when constitutional rights are violated.

But these principles come with a few caveats:

First, it is not meaningful to talk of a simple or single meaning for a document that resulted from difficult compromises. The Constitution was arguably ratified because different people understood its language in different ways. The Federalist Papers were written because the constitutional interpretation of the Federalists was not universally held. What did “to regulate commerce” mean to the Founders? Their answer would probably come in the form of a good debate. Judges must sometimes rely on the plain meaning of words, which define a margin of honest interpretation rather than requiring a single interpretation.

Second, America effectively had two sets of Founders — those who wrote and approved the Constitution, and those who wrote and approved the 14th Amendment, which corrected a near-fatal flaw in the document. True originalism must take seriously that, in the 19th century, the ideals of the Declaration of Independence invaded the Constitution and changed the meaning of the American experiment.

Third, the principles of originalism and of deference to democracy are sometimes in tension. If a judge feels the law has strayed badly from constitutional principles, he or she will be less likely to embrace judicial modesty. This will, on occasion, activate even the least activist judges. And it means we often apply the doctrine of deference more vigorously to protect favored outcomes.

Choosing the right person to prudently navigate these challenges is massively important. But our democracy would probably be healthier if the stakes were lower — if difficult issues were returned to the democratic realm and the Supreme Court descended from Olympus.