As Special Counsel Robert Mueller puts the finishing touches on his office's nearly-two-year-old inquiry into various aspects of the president's alleged wrongdoing, Democrats in Congress are angling for their own sneak preview before his report goes into wide release. On Monday, House Judiciary chair Jerry Nadler issued formal requests for documents to 81 Trump-affiliated individuals and organizations, as part of an investigation into what he called "a number of actions that threaten our nation's longstanding commitment to the rule of law, including allegations of obstruction of justice, public corruption, and other abuses of power." For now, he is asking nicely; those who do not comply within two weeks can expect to receive a subpoena that requires their cooperation.

At first glance, these demands may seem redundant with Mueller's work. Notably, the list includes several figures who have already been convicted of Oval Office-adjacent crimes (Paul Manafort, Rick Gates, George Papadopoulos, Michael Flynn, and remorseful oaf Michael Cohen), as well as others who might be nervous about their own legal status (Carter Page, Julian Assange, Jerome Corsi, and unsettling tattoo-haver Roger Stone). It seems unlikely that this process yields a groundbreaking admission from, say, former White House chief of staff Reince Priebus that Mueller did not learn long ago.

But by collecting this information himself, Nadler is preparing for the possibility that Mueller's findings fall victim to an eleventh-hour cover-up. In fact, the mere act of issuing the letters serves as a de facto warning to new Attorney General William Barr, and as a check on potential abuses of his authority. The special counsel's office owes its existence to then-attorney general Jeff Sessions, who concluded on the advice of career ethics officials that his own involvement in the campaign's Russia dalliances prevented him from overseeing the Department of Justice's investigation. Neither Sessions' interim replacement, novelty toilet salesman Matthew Whitaker, nor his permanent successor, vocal Mueller critic Barr, are similarly constrained, which raises obvious questions about whether they will respect its independence at such a critical juncture. Barr fueled this speculation during his confirmation hearing, when he declined to pledge to abide by the recommendations of ethics officials or release a full, Starr Report-esque account of Mueller's findings.

The existence of a separate, robust, subpoena-backed House investigation, however, presents Barr with a more difficult choice. If the attorney general opts for transparency, allowing Americans the opportunity to obtain answers about this administration's many enduring mysteries. If he elects to prevent the disclosure of important information—particularly as the nation prepares to decide whether to re-elect the president to a new four-year term—Nadler can just reveal it himself, while also portraying Barr as complicit in efforts to shield the president from meaningful accountability.

It also appears that Michael Cohen's answers to pointed questions from Alexandria Ocasio-Cortez, among others, have had an immediate impact. Among the recipients of today's batch of correspondence are American Media Inc. executives David Pecker and Dylan Howard, whom Cohen named as individuals with knowledge of the National Enquirer's catch-and-kill scheme for stories embarrassing to Donald Trump. Also on the list were Trump Organization officials Allen Weisselberg, Ron Lieberman, and Matthew Calamari, whom Cohen said could shed more light on how their boss inflated and deflated his real estate assets in order to, respectively, defraud insurance companies and avoid property tax liability.

I expect few people on this list to willingly comply with Nadler's demands, or to provide anything more than indignant objections and cursory responses unless and until they receive a subpoena. (For the likes of Eric Trump, Jared Kushner, and especially Don Jr., for whom acquiescing to the demands of Democrats would forever foreclose the possibility that his father might one day tell him he loves him.) And for now, Nadler's requests to the Weisselberg-Lieberman-Calamari are limited to issues related to the 2016 election: the Stormy Daniels scandal, Russian investments in Trump's family businesses, and efforts to facilitate the construction of Trump Tower Moscow. The president's alleged financial crimes, for now, remain outside the scope.

Nevertheless, this mail dump sends the strongest signal yet to the president's associates that this Congress intends to exercise its constitutional oversight responsibilities to a degree that the last House, under Paul Ryan's leadership, could never be bothered to do. They might avoid getting swept up in Mueller's criminal investigation, or escape mention in whatever watered-down report Barr authorizes for publication. Now, they must grapple with the fact that House Democrats—who do not answer to anyone in the Department of Justice—are doing everything in their power to bring those misdeeds into the light.