Dismissed by Donald Trump Jr.'s legal team as little more than a Russian "nothingburger," the controversy over the Trump campaign's meeting with a Kremlin-linked lawyer could shape up into a whopper of a federal criminal case.
Legal experts cite violation of campaign finance laws, conspiracy to defraud the United States and conspiracy to commit bribery as areas of criminal exposure for key members of the president's inner circle.
The controversy has also sprinkled more crumbs for the investigative team led by special counsel Robert Mueller, who is reportedly reviewing Trump Jr.'s emails and the meeting as part of the broader probe into ties between President Donald Trump's campaign and Russian officials.
Before Trump Jr. posted a chain of potentially self-incriminating emails on Tuesday, questionable legal advice may have prompted him to voluntarily confirm taking the meeting to gather dirt on Hillary Clinton, his father's Democratic opponent.
The emails were first obtained by the New York Times.
"It's very clear what's going on," Richard Painter, the former chief White House ethics lawyer under George W. Bush, told CBC News. "The Trump campaign was willing to do whatever it took to win, and they were willing to get information from the Russians about Hillary Clinton. And that's why [Trump Jr.] went to that meeting, and there's potential exposure into various criminal statutes."
Legal scholars were left scratching their heads about why Trump Jr. would reveal he met last June with Natalia Veselnitskaya, described as a "Russian government lawyer," after learning of her promise to provide information that could "incriminate" Clinton.
'I'm not sure I would advise disclosing that'
"If I was his lawyer, I'm not sure I would advise disclosing that," said Barak Cohen, another former federal corruption prosecutor now with the Washington law firm Perkins Coie.
On Tuesday, Trump Jr. released an email chain disclosing more details of his arrangements for the meeting, which included a section indicating he was receptive to the Russian government, a foreign adversary, helping his father's campaign.
Here's my statement and the full email chain pic.twitter.com/x050r5n5LQ— @DonaldJTrumpJr
Here is page 4 (which did not post due to space constraints). pic.twitter.com/z1Xi4nr2gq— @DonaldJTrumpJr
"He's potentially opening himself for liability," Cohen said, noting that the emails also loop in then-Trump campaign manager Paul Manafort as well as Trump's son-in-law Jared Kushner, who attended the gathering at Trump Tower. Their names are now linked in a paper trail to the scandal as well.
"I don't like to call it a smoking gun, but it's a building block" toward a potential case for showing campaign collusion with the Russians, Cohen said.
"You don't have anything there saying: 'I, Donald Trump Jr., attempted to collude with the Russians.' What you have is indications of his knowledge the Russians were trying to interfere with the election and even, arguably, some indication he was open to the idea."
That email disclosure is more important from "an intent and knowledge" perspective, Cohen said. It informs Trump Jr. that "the Russian government is interested in interfering with the election, and it seems to express his interest in at least entertaining involvement of the Russian government."
Last year's emails between Trump Jr. and music publicist Rob Goldstone, who arranged the meeting, explicitly say the offer of dirt on Clinton "is part of Russia and its government's support for Mr. Trump."
Trump Jr. wrote in response, "I love it."
While Trump Jr. insists no useful information was provided, the correspondence shows he was not only willing to meet with Veselnitskaya to get dirt on Clinton, but he went further by acting to set up the meeting.
"It's enough to point to Kushner and Manafort to be involved in any illegal conduct as well," Cohen said.
The central argument for making a case that Trump Jr. — and the campaign itself — violated federal campaign finance laws rests in the statute prohibiting foreign nationals from providing a contribution or financial donation "or other thing of value" to a campaign.
"The problem for Donald Trump Jr. is it certainly seems like his response to that email setting up that meeting is soliciting that kind of contribution," said Ryan Goodman, a law professor at New York University and a former special counsel at the Department of Defence during the Obama administration.
"That is what the campaign finance law criminalizes — solicitation."
Goodman said that means it doesn't matter whether the Russian lawyer's purported information on Clinton provided any "thing of value" because Trump Jr. appeared to solicit the information "because he responded affirmatively to the meeting accepting that information."
"Even if it's not treason, it's solicitation of criminal foreign involvement in a U.S. national campaign, and conspiracy to violate federal campaign laws," said Laurence Tribe, a professor of constitutional law at Harvard Law School.
Trump Jr. said the June 2016 meeting was primarily about Veselnitskaya's concerns about the Magnitsky Act, which blacklists suspected human-rights abusers.
Depending on the content of the discussions last year, Tribe said, another case could be made for conspiracy to commit bribery "by trading foreign campaign help from the Kremlin, for help to the Kremlin" by lifting sanctions against Russian oligarchs.
The Russian lawyer story came to the attention of the New York Times after Kushner, Trump's son-in-law and senior adviser, revised his security clearance statement after initially failing to report the sensitive meeting.
Depending whether or not it's viewed as an innocent oversight, Goodman said, "to neglect to include that information" about meeting a potential adversary that could influence the election "seems quite significant and is a crime."
The White House has repeatedly denied any allegations of collusion with the Kremlin.
The Times has said Trump Jr. released his emails after being informed by the newspaper that it had seen them.
Some Republicans dismiss controversy
Congressional Republicans came to the defence of the president's eldest son, though some conceded it would be best for him to testify before a Senate intelligence panel to clear the air.
"Frankly, I think that's overblown," Utah's Orrin Hatch told reporters, describing Trump Jr. as "a very bright young man." He bristled at suggestions from Democratic Senator Tim Kaine and other critics who brought up treason, saying that characterization was far too strong.
Other Republicans such as North Carolina's Thom Tillis and Texan John Cornyn dismissed the controversy as a distraction from legislative business such as passing a Senate health-care bill.
The president, who until now has been conspicuously quiet on the issue, released a statement defending his son as a "high-quality person," adding, "I applaud his transparency."