From the New York Times:
President Trump’s eldest son, Donald Trump Jr., was promised damaging information about Hillary Clinton before agreeing to meet with a Kremlin-connected Russian lawyer during the 2016 campaign, according to three advisers to the White House briefed on the meeting and two others with knowledge of it.
The meeting was also attended by his campaign chairman at the time, Paul J. Manafort, and his son-in-law, Jared Kushner. Mr. Manafort and Mr. Kushner recently disclosed the meeting, though not its content, in confidential government documents described to The New York Times.
The Times reported the existence of the meeting on Saturday. But in subsequent interviews, the advisers and others revealed the motivation behind it.
The meeting — at Trump Tower on June 9, 2016, two weeks after Donald J. Trumpclinched the Republican nomination — points to the central question in federal investigations of the Kremlin’s meddling in the presidential election: whether the Trump campaign colluded with the Russians. The accounts of the meeting represent the first public indication that at least some in the campaign were willing to accept Russian help.
While President Trump has been dogged by revelations of undisclosed meetings between his associates and the Russians, the episode at Trump Tower is the first such confirmed private meeting involving his inner circle during the campaign — as well as the first one known to have included his eldest son. It came at an inflection point in the campaign, when Donald Trump Jr., who served as an adviser and a surrogate, was ascendant and Mr. Manafort was consolidating power.
It is unclear whether the Russian lawyer, Natalia Veselnitskaya, actually produced the promised compromising information about Mrs. Clinton. But the people interviewed by The Times about the meeting said the expectation was that she would do so.
The short version of this is that the Trump people set up this meeting with the Russian based on the promise that they would get dirt on Hillary Clinton, that the story itself was confirmed by people in the White House, and that despite all the denials up to now about collusion with the Russians on the campaign, they were at least interested in looking into it. It’s also telling that Trump Jr. made a point of saying that his father knew nothing about the meeting. If the meeting turned out to be a nothing-burger, as he now claims it was, then why is he making the point that Trump Sr. didn’t know about it? Even with its most innocent interpretation — hey, this crazy Russian lawyer promised us the moon and we got bupkus — doesn’t sound like something you need to insulate him from unless you’re aware of the fact of how it might look if it got out.
It doesn’t really matter if nothing came of this meeting or if Ms. Veselnitskaya was just blowing smoke up their asses or even if they thought she was some kind of whack-job. The fact that they took the meeting at all no matter what tells you a lot, including what the Trump people were willing to do to win the election.
So to answer the question, I’d call it treasonable.