Two issues.
The first is that Trump appears to have broken some new ground here when it comes to admitting the true purpose of the Trump Tower meeting with a Kremlin-aligned lawyer — and even further contradicted the initial statement he helped draft about it. At the time, Donald Trump Jr. issued a statement explaining that he and the lawyer, Natalia Veselnitskaya, had “primarily discussed a program about the adoption of Russian children.” We have since discovered that the elder Trump actually dictated that statement.
.. Quickly, though, that explanation fell apart, and we learned that Trump Jr. had actually been promised harmful information about Democrats, including Hillary Clinton. The president himself seemed to shrug it off, saying in July 2017 that, “from a practical standpoint, most people would have taken that meeting.” He added: “It’s called opposition research or even research into your opponent.” (Trump also tweeted along these lines.) But at the same time, he still suggested that the meeting was, in large part, about adoption.
.. If you’re Robert Mueller and you’re looking at whether Trump obstructed justice, you’ve now got even more evidence of a clear attempt to mislead the public and obscure the truth. Trump’s July 2017 comments came before we knew he was involved in drafting that initial misleading response, and they don’t so precisely say the meeting was intended to get oppo; now there is really no disputing that point if you’re Trump’s lawyer. (It’s a little like Trump’s Lester Holt interview, in which he said Russia was on his mind when he fired James Comey. That may not be the same, legally speaking, as him saying he fired Comey because of the Russia investigation.)
.. One of the strangest things about our free-wheeling Tweet presidency is that Trump routinely admits/acknowledges things, in writing, that might require hard-fought testimony from other presidents. As he did today with motive of Trump Tower meeting.
..The second issue here are the final words of the tweet. “I did not know about it!” This is something Trump has said regularly about the Trump Tower meeting and something he has re-upped now that Michael Cohen is reportedly telling people that Trump did know about it.
.. But here’s the thing: This is a tweet about how the Trump Tower meeting was totally fine — nothing illegal to see here. If you’ve got no real concern about legal exposure from the meeting, why distance yourself from it? Trump seems to be arguing against his own point by assuring us that he had nothing to do with this meeting, which — oh, by the way — was totally on the up-and-up.
.. Is this tweet, in and of itself, damning? Probably not. But obstruction-of-justice cases are about proving that someone had “corrupt intent” when they took the actions they did. And for the second time in less than a week, Trump tweeted something that suggested his intent wasn’t terribly wholesome. He also suggested that he isn’t as convinced as he’d like us to believe that there’s nothing to see here.