Enter stage left, Thomas à Becket. The Archbishop of Canterbury, murdered a millennium ago on his cathedral’s floor, appears in Special Counsel Jack Smith’s latest brief to the District of Columbia Circuit of the United States Court of Appeals requesting a gag order on President Trump.

In seeking to secure a prior restraint against the 45th president,  Mr. Smith compares Mr. Trump’s rhetoric on Truth Social to  King Henry II’s remark, “Will no one rid me of this meddlesome priest?” That royal query — or invitation — made on Christmas Day in 1170 is reported by a monk who was injured alongside Becket when the prelate was murdered.

The tale draws into high relief the extent of the responsibility borne by figures of power — a king, say, or a former president — for the consequences of their commentary. A question Henry asked the realm changed the course of the Middle Ages. What of the musings of Mr. Trump, frontrunner for the Republican nomination for president and a criminal defendant four times over?  

Henry’s question, while not explicitly a command, drove four knights to journey to Canterbury from Normandy to slay Becket, with whom the king had a long-running feud over the church’s prerogatives. Two years after the priest was murdered, he was canonized by Pope Alexander III. Henry reigned for 56 years, the longest of any English monarch until George III centuries later. 

Becket’s martyrdom would inspire everything from “The Canterbury Tales” to the Becket Fund for Religious Liberty to T.S. Eliot’s verse drama, “Murder in the Cathedral.” Now, it is also animating Mr. Smith, who, in a moment of vainglory, appears to liken himself to the sainted and martyred Becket, whose name adorns churches the world over.

A professor at Harvard, James Simpson, tells the Sun that the “citation of Henry II is perfect —  it’s the locus classicus for indirect orders: an ostensibly innocent interrogative masking an imperative.” He adds that it is “time to remember the power of words and time to remember Henry II.”  

Yet Mr. Smith offers the court fear rather than facts. By linking Henry’s question to Mr. Trump’s heated rhetoric — yesterday, the former president speculated that the special counsel will end up in a mental Institution “by the time my next term as President is successfully completed” — Mr. Smith aims to persuade the D.C. Circuit to ratify Judge Tanya Chutkan’s gag order, which is stayed pending this appeal. 

Mr. Trump has taken advantage of the gag order’s temporary pause. At a rally last weekend, the former president called Mr. Smith “deranged” and a “Trump-hating prosecutor,” and ventured that the special counsel’s “wife and family despise me much more than he does.” In requesting a gag order, Mr. Smith cited the example of a woman who sent Judge Chutkan voice messages promising to “kill anyone who went after former President Trump.”

Mr. Smith’s contention is that “targeted disparagement” — cue Becket’s fate — poses a “danger even when it does not explicitly call for harassment or violence, as repeated attacks are often understood as a signal to act.” The jurists who sit above Judge Chutkan are now tasked with discerning whether that danger is substantial enough to infringe on Mr. Trump’s First Amendment rights. Those are thrown into sharp relief by his candidacy for president. 

This is not the first time that Becket’s momentous murder has fetched up in court. A footnote in a case out of Virginia from 2005 provides a postscript. There, a district judge, T.S. Ellis III, writes, “Henry paid dearly for his wayward words” because the killing “aroused such great public sentiment against Henry that he was forced to perform penance.”

The penance, Judge Ellis III writes, included a “pilgrimage to Canterbury, walking the last three miles on bare bleeding feet” and “allowing the monks to scourge” his royal person while he “lay prostrate at Becket’s tomb.” The quartet of assassins themselves were disinherited, excommunicated, and ordered to serve 14 years of penance in the Holy Land.

The stakes for Messrs. Smith and Trump in this appeal, though, go beyond mere exercises in medieval lore. If Judge Chutkan’s gag order is reaffirmed, the former president will be required to watch his mouth before and during his trial at her courtroom, set for March 4. She has promised sanctions if the order is violated, which could include prison.   

A second Henry would join Henry II as Becket’s foe. Nearly 400 years after Becket’s killing, Henry VIII, in his break with the Church, would destroy Becket’s shrine at Canterbury and scatter his relics to the winds. A word of caution, possibly, for Mr. Smith. Saints, as well as special counsels, can be undone by a new administration bearing an old name.