The man who could be the most famous in the world is facing a battery of investigations unfolding under sealed secrecy. That strange set of affairs clicked into place with a CNN report that no less than eight investigations into President Trump are underway. Our concern is less with the former president’s chances for a return to the White House than with the prospect of a bonfire of legal privileges that undergird our due process of law. 

Some of special prosecutor Jack Smith’s targets have leaked. Among them is Vice President Pence, who has declared his intention to seek shelter under the speech or debate clause in asserting that the office he held — president of the Senate — is part of the legislature whose members are accorded by the Constitution protection against being questioned in “any other place.” Speech or debate is not available to Mr. Trump, who is seeking executive privilege. 

Another name that has been disclosed, but that is under seal, is that of Mr. Trump’s attorney, Evan Corcoran. Normally, conversations between a client and an attorney are privileged, meaning protected from being grist for prosecution. The Supreme Court calls it one of the “oldest recognized privileges in the law.” Mr. Smith is trying to pierce that protection by arguing, the Times reports, that Mr. Corcoran was party to a crime. The lawyer has hired his own lawyer.

The cases under seal involve grand jury deliberations, filings and decisions, and bushels of briefs, all obscured from the public. The Department of Justice has argued that it “may well be necessary for a court to more frequently decline to release judicial opinions ancillary to grand jury investigations that are the subject of intense press attention.” Our colleagues in the press have pushed for access in the name of a “profound national interest” in disclosure.

Mr. Smith is not the only keeper of secrets. Further indictments await under seal at Fulton County, Georgia, where a redacted grand jury report only hinted at suspicions of perjury and found no evidence of fraud in the 2020 presidential election. The jurors note, however, that they “set forth for the Court our recommendations on indictments and relevant statutes.” The district attorney, Fani Willis, has said only that charging decisions are “imminent.” 

We understand the need for discretion, and too much sunlight can be hazardous for due process. For that proposition, we cite the tell-all of a former prosecutor, Mark Pomerantz, “The People vs. Donald Trump.” Another prosecutor, Andrew Weissman, no friend of President Trump, noted how the book is “certainly going to be used in countless ways by the defense, including to claim selective prosecution.” It strikes us as an ethical, and opportunistic, breach.

Still, as an op-ed in the Times put it, “we need to prepare for a first in our 246-year history as a nation: The possible criminal prosecution of a former president.” Mr. Smith looks set to move on Mr. Trump, and doing it in stealth amounts to legal guerrilla tactics that can only do damage to our wider democratic faith. The only secret about Mr. Trump’s future ought to be the ballots that Americans cast in voting booths to decide the political verdict.