Why was it so “stunning” — to use our headline word — for Jack Smith to dismiss the criminal cases he’s been pursuing against President Trump? The answer, in our view, is that the motions disclosed that Attorney General Garland knew when he launched the special prosecutor that Donald Trump was running for a second term. He knew it would be forbidden to go after a sitting president. Yet he plunged ahead — a decision that could only be political.

Which is why the Sun has been pressing that point from the beginning — in a remarkable series of almost daily news dispatches by our Ari “A.R.” Hoffman and in editorials on the constitutional principles that surfaced over the course of these cases. It was on November 16 that President Trump announced he would stand for reelection. It was two days later that General Garland reacted by appointing Mr. Smith as special prosecutor.

Thus was this ending nigh inevitable. Democrats blew past one warning light after another. The House January 6 committee laid the groundwork, violating the constitutional prohibition against holding a trial in the legislature. The committee pronounced Trump guilty and sent the particulars, such as they were, over to the Justice Department. This evidence, tainted by attainder, was used  to inform the case against Trump. Attainder be damned.

Americans subsequently learned that the very week that General Garland named the special prosecutor, the Justice Department was meeting with the prosecutor, Nathan Wade, hired by District Attorney Fani Willis to prosecute President Trump in Georgia. Mr. Wade, who subsequently resigned over his relationship with Ms. Willis, took meetings with the White House counsel. Will Ms. Willis follow Mr. Smith’s retreat, or instead retrench?

Mr. Garland’s headaches go beyond Mr. Smith. The Supreme Court narrowed the use of an obstruction charge derived from the Sarbanes-Oxley Act against January 6 rioters, and Trump has promised to pardon at least some of those defendants when he returns to the White House. It takes no defense of Trump’s behavior — or of theirs — to see that the American people delivered a verdict on all of this on November 5. 

Even as Mr. Smith headed toward the exit, he insisted in the January 6 motion that he fully stands behind “the strength of the government’s proof or the merits of the prosecution.” He repeats, for a second time in that filing, that the “outcome is not based on the merits or strength of the case against the defendant.” His motion that the cases be dismissed “without prejudice” could mean that the special counsel harbors hope of refiling again.

That maneuver reminds us of the tack taken by District Attorney Alvin Bragg, who has urged Judge Juan Merchan to pause his case for the next four years and explore “non-dismissal options.” Mr. Bragg knows that he cannot prosecute a sitting president, so he wants his 34 convictions frozen for four years, only to spring back to life in 2029. We call that a “Sword of Damocles” approach that would injure what Scalia called “the boldness of the president.”

The American people aren’t dumb. They can see that presidential boldness could also be rattled by letting immunity be only temporary. That is clearly a hope of Mr. Smith, who today cites the “temporary nature of the immunity afforded a sitting President.” He avers that Trump’s term “does not require dismissal with prejudice.” Yet the vast jury of the  American people voted with full knowledge of Mr. Smith’s cases. We have called the result an “acquittal” — with, let us add,  prejudice.