President Trump’s gamble to use the lifeboat of the Constitution is, at least to us, a newsworthy development. That bet on American bedrock comes in a motion to dismiss the charges against him on the bases of presidential immunity, double jeopardy, and the impeachment clause. In a silly season, this is serious stuff. We don’t mind observing that it is a constitutional interpretation that we’ve championed. 

We are no judges, but to look into the text of the national parchment is to find that the “Party convicted” of impeachment “shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.” What of Mr. Trump, though, who was acquitted — discovered by the Senate to be “not guilty”  — on the basis of the same underlying facts for which Special Counsel Jack Smith now seeks convictions? 

That question — which now is ripe before Judge Tanya Chutkan’s bench — was pondered in a Department of Justice memorandum from 2000. While government lawyers found that the Constitution “permits a former President to be indicted and tried for the same offenses for which he was impeached by the House of Representatives and acquitted by the Senate,” one can practically feel the department memo trembling with uncertainty. 

The memo grants that the constitutional language is “ambiguous” when it comes to the immunity of persons acquitted by the Senate. It allows that the case for immunity — Mr. Trump’s case, though the memo predates it — “has some force” and that there are “reasonable arguments” on its side. The case is “more complicated than it might first appear.” One imagines that the memo’s author, Randolph Moss, now a federal judge, could easily have argued the opposing view.

Judge Moss almost does. In the memo’s final paragraph, he writes that “we think that there is a reasonable argument that the Impeachment Judgment Clause should be read to bar prosecutions following acquittal by the Senate.” While ultimately finding that such immunity does not hold, Mr. Smith cannot be too pleased with the mien of mystery that attaches to the question. The constitutional cookie could well crumble otherwise.

We don’t mind noting that it was our A.R. Hoffman who, as far as we can discern, first noted the possibility that an impeachment acquittal could stand Mr. Trump in good legal stead, and we have returned to this question with regularity because the plain text of the Constitution seems to mean that an acquittal is an acquittal. The Framers could very well have run a quill through the word “convicted.” They did not. The burden would appear to be on those who proceed as if they had.

We are glad for Mr. Trump’s motion. Not because we carry any brief for his behavior on January 6, but because it could be a constitutional opportunity that comes along rarely — to get under the hood of the system devised by Hamilton and Madison. Mr. Trump’s case could help clarify what is unique about the presidency, and what he holds in common with every other defendant — the promise of due process.