Remarkably, the Court's output is subject to later editing by the Justices, sometimes years after Opinions are released for public consumption. Changes have been made by Justices of all persuasions, across the range of judicial philosophies they represent, long ago and recently. They are often, but not always, merely grammatical or typographical. But the changes are never made public; they simply appear different in print in the only "official" reports of the Court. Astoundingly, for these judges who know best-of-all the power of words, and who are the protectors of free expression and the liberties promised in the Bill of Rights nobody on the Court seems to have a problem with that.
Now, you don't get to be a Supreme without a sublime facility for argumentation, a stickling for minute detail and nuance, and an ego that suggests to you that you're precisely the decision-maker the Court needs among its members. Those qualities all contribute to the Court's wordy output. They may also contribute to a blind spot that allows them to pursue these do-overs, and tolerate their use away from the public eye.
The Justices, though, might hazard a glance at the Code of Conduct for United States Judges. Canon Number 2 reads, in part, as follows:
• CANON 2: A JUDGE SHOULD AVOID IMPROPRIETY AND THE APPEARANCE OF IMPROPRIETY IN ALL ACTIVITIES
1. (A) Respect for Law. A judge should respect and comply with the law and should act at all times in a manner that promotes public confidence in the integrity and impartiality of the judiciary…
I would submit that these changes, done in private, unnecessarily risk undermining the popular confidence and respect the Court needs, especially in this era of amply-justified low trust in government motives, capabilities and actions. I am not suggesting that history has been getting a rewrite here the evidence is to the contrary. The judicial standard, though, is to avoid even "the appearance of impropriety," precisely because judges must command respect they are uniquely the Caesar's wife of governance.
Most of the corrections do not go to meaning. Some mistakes are purely technical errors in spelling, case citation, punctuation or grammar that have no conceivable substantive impact. Correction of them may also be trivial on the merits, but rampant perfectionism might demand it. (In the spirit of disclosure, I've been known to edit even these humble missives post-publication, when I find similar problems -- just because.)
A second variety is factual errors that also do not have any impact on interpretation as in an event out of sequence. These might also be classified as harmless error, with the fix done simply to "set the record straight."
Finally, there are errors that might conceivably alter the substance of an Opinion. They might also be technical or factual as well, but their possible effect is the critical criterion, here. For example, a comma might be technical only, or it could save a life (as in the famous "let's eat, grandpa" vs. "let's eat grandpa"). These are the least common corrections, but by far the most dangerous. They represent a slippery slope that should not be entered -- to avoid not only the appearance but also the fact of actual impropriety. Here are a few examples of these shades of difference, again from across the spectrum of judicial philosophy. Fortunately, there are no recent examples of wholesale rewrites.
If no change to this process occurs, is the republic likely to come crashing down? No, but this IS a matter of leadership by example an indication that government processes should be public and transparent to all concerned.
The fix here is simple: provide transparency that demonstrates the absence of impropriety. Every day, the government publishes the Federal Register of actions taken or rules proposed or finalized by the feds. The Court could publish there, or in a separate notice of its own making. The key is to make it public, thereby eliminating Any suspicion about the Court's actions. It's the right thing to do, it serves an important purpose, and it costs next to nothing.
Conversely, technology exists to "machine-grade" earlier vs. later editions of opinions for consistency, letter by letter. That is the kind of task at which computers excel they work unerringly and tirelessly. The Court would do well to get ahead of this issue and avoid any self-inflicted wounds to its precious credibility. Justice should be both blind, and free of blind spots.