The $1 million inaugural gift came from a Northern Virginia company called BH Group, LLC. Unlike other generous corporate inaugural donors, like Bank of America and Dow Chemical, though, BH Group was a cipher, and likely was set up solely to prevent disclosure of the actual donor’s name.

Almost nothing is known about the company, including who runs it or its reason for being beyond writing a seven-figure check on Dec. 22, 2016, almost a month before Trump was sworn in.

While the source of the money used to make the gift was masked from the public, a trail of clues puts the contribution at the doorstep of some of the same actors — most notably Leonard Leo, an executive vice president at the conservative Federalist Society — who have helped promote Trump’s mission, and that of his White House counsel, Don McGahn, to fill judicial vacancies as quickly as he can with staunchly conservative, preferably young jurists.

Set up four months to the day before it made the donation, BH Group’s address, as given in its Virginia incorporation papers, is a virtual office in Arlington, Va.; the only person identified on the filing is a Donna Smith.

That name, while common, matches the name of a longtime paralegal at the political law firm Holtzman Vogel Josefiak Torchinsky, whose Warrenton, Va., office was listed as the Trump inaugural committee’s main address on the tax return it filed last February.

Holtzman Vogel is a Republican firm known for specializing in creative legal maneuvers that allow donors to conservative causes to remain anonymous, at least to the public.

In March, when a reporter tried to speak with Donna Smith about the BH Group, Michael Bayes, a partner at the firm, responded instead, saying “We don’t have any comment on client matters.”

Another connection to the BH Group was revealed in November 2017, when a politically active nonprofit called the Wellspring Committee filed tax documents showing a $750,000 payment to the newly-minted firm for “Public Relations.”

That’s a substantial payment, particularly given that the BH Group does not appear to have marketed itself as a public relations firm. The group doesn’t seem to have a website or any listings that advertise its services.

Similarly, the Wellspring Committee is a notoriously secretive Virginia nonprofit, with no demonstrable public-facing operations, no website for publicizing them and only three employees.

It’s also not clear why a group like Wellspring would need costly public relations assistance. Its representatives did not respond to requests to comment for this story.

The group only has a single board member, Neil Corkery, and almost all of its money in 2016 went out the door as grants to other conservative organizations or as payment to the BH Group.

Wellspring was practically the sole funder in 2016, to the tune of nearly $23.5 million, of the Judicial Crisis Network — a group that poured millions into stopping the Senate from confirming former President Barack Obama’s Supreme Court pick in the last year of his term, leaving an open slot for Trump to fill.

Legally, experts say there would be no problem with the Wellspring Committee giving $750,000 to the inaugural committee directly or, likely, giving it to the BH Group for that purpose; it’s not clear that straw donor rules apply to inaugural committees.

However, Wellspring’s characterization of the payment might raise issues for the nonprofit, if the check wasn’t in fact for services rendered.

If Wellspring “intentionally misrepresented the payment” on its tax filing, said Lloyd Mayer, a tax professor at the University of Notre Dame, in an email, “that would in theory raise perjury concerns.” The IRS, however, rarely pursues cases based on inaccuracies in an organization’s tax filings.

At the center of the convoluted network through which the inaugural contribution flowed is Leonard Leo, the executive vice president at the Federalist Society, one of the nation’s most influential conservative legal organizations — to which some say the White House has outsourced its judicial nomination process.

For example, when then-Supreme Court nominee Neil Gorsuch was asked how he had come to Trump’s attention, he wrote, “On about December 2, 2016, I was contacted by Leonard Leo.”

Steven Calabresi, a Federalist cofounder and board member, told The Hill last year that Leo’s work offering guidance to the White House is solely in his capacity as an individual citizen.

But helping him in this task, according to the New York Times, is lawyer Ann Corkery, the wife of Neil Corkery, the Wellspring Committee’s president. Ann herself was president of Wellspring from its founding in 2008 until 2015.

The assistance between Leo and the Corkerys goes both ways. According to one source close to the three of them, Leo is directly involved in raising much of the anonymous money the Wellspring Committee brings in every year.

None of the three responded to requests for comment.

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Though the source couldn’t confirm Leo’s role in the BH Group, Leo himself recently made the connection in a campaign finance filing reported to the Federal Election Commission: He listed “BH Group” as his employer.

It’s unlikely that Leo himself is the source of the $1 million, but his role at the Federalist Society allows him to meet and mingle with some of the wealthiest conservative donors in the country. The organization counts among its funders conservative billionaires like Charles and David Koch, as well as industry groups like the Chamber of Commerce and Fortune 500 companies like Walmart and Pfizer, according to its 2017 annual report.

Leo and another vice president at the Federalist Society, Jonathan Bunch, are also involved in a nonprofit called the BH Fund. A public records request by alumni and students at George Mason University shows that the BH Fund was set up to enforce a donor agreement with GMU’s Antonin Scalia Law School on behalf of an anonymous donor who pledged $20 million to the program, according to a report last year from Buzzfeed.

Last month, GMU’s president Ángel Cabrera — who has come under pressure for allowing donors to dictate conditions in return for financial gifts — said that some agreements the school accepted in return for contributions “fall short of the standards of academic independence.”

The donor providing the $20 million that Leo’s BH Fund administers is “low-profile, very wealthy and on the young side,” a source told McClatchy. But he or she is still anonymous.

As is the $1 million donor to Trump’s inauguration. Anonymous, that is, to the public.

“The public doesn’t know who is behind this million-dollar donation,” Brendan Fischer of the Campaign Legal Center wrote in an email, “but the Trump administration very likely does. Special interests tend to give to an inauguration in order to buy influence, so whomever is behind this $1 million check presumably made their identity known to the incoming administration.”

“It is hard to imagine,” he went on, “that this anonymous donor funded the inauguration simply because they were dying to see 3 Doors Down perform at the Lincoln Memorial.”

Special McClatchy Correspondent Peter H. Stone contributed to this story.