Last week, the New York Times reported on how special counsel Robert S. Mueller III is looking at President Trump's tweets as potential evidence in an obstruction of justice case.

On Wednesday, Trump gave him more potential evidence.

In a tweetstorm, Trump called upon Attorney General Jeff Sessions to shut the whole Mueller probe down — the first time he has done that. It wasn't altogether surprising, given that his lawyer Rudolph W. Giuliani has called for the investigation to be closed. But it was notable because it came directly from Trump this time, and his call focused on Sessions.

The attorney general has recused himself from the matter because of potential conflicts of interest, on grounds that he campaigned for Trump. So Trump is apparently calling for Sessions to un-recuse himself from a case in which he has acknowledged he cannot be seen as neutral, and then to end it.

In defending the tweet, Trump's lawyers told The Post that it wasn't an explicit command. “He carefully used the word, 'should,'" Giuliani noted. Trump's personal lawyer Jay Sekulow added: “The president has issued no order or direction to the Department of Justice on this.”

But that cleanup effort betrays the problematic nature of the tweet. And this is hardly the first time that Trump has broadcast a desire to change the course of the investigation. Whether any of those tweets rise to the level of obstruction of justice or may be used to build such a case, we don't know. But Trump has clearly played with fire — and is continuing to do so.

Let's review other tweets that could similarly factor into the obstruction probe, ranked by how troublesome they seem to be.

1. The Flynn tweet

This is a big one, and it was so problematic that the Trump team was forced to argue that Trump didn't actually send it (aides blamed it on attorney John Dowd).

The problem is basically this: Shortly after Trump fired Michael Flynn as national security adviser in February 2017, he suggested in a private meeting that then-FBI Director James B. Comey be lenient on Flynn, according to Comey's testimony under oath. (“I hope you can let this go,” Comey quoted Trump as saying.) If Trump knew at that time that Flynn had lied to the FBI — to which Flynn later pleaded guilty — it would make for a more compelling argument that he was trying to obstruct an investigation of Flynn and, by extension, protect himself.

Trump's legal team told Mueller in January that Trump “had every reason to believe at that time that the FBI was not investigating Lt. Gen. Flynn,” according to a memo obtained by the Times. That's yet another indication that the lawyers see how troublesome it would be if Trump knew Flynn was under investigation at the time.

2. “I fight back”

In this April 2018 tweet, Trump appears to acknowledge that the actions that some have construed as potential obstruction of justice are actually just examples of “fight[ing] back.” But that's also Trump acknowledging that he is acting in his own self-interest — rather than for other, less obstruction-y reasons such as promoting good government.

The tweet echoed a January interview with ABC News's Jonathan Karl in which Trump explained, “You fight back. Jon — you fight back.” Trump then mockingly quoted his opponents: “'Oh, it's obstruction.'”

Given all that, it's totally reasonable to ask whether events such as firing Comey were Trump “fighting back” — rather than getting rid of an FBI director who had lost the faith of his agency, which was the initial explanation.

3. The Sessions tweet

See above.

4. “Expose what they are doing”

It's one thing to decry the “witch hunt”; it's another to issue a call for action against it. Much like Trump calling for Russia to hack Hillary Clinton could be a key moment in the collusion investigation, calling for Republicans to “expose what [Mueller's investigators] are doing” sounds a lot like he's trying to damage the investigation.

Perhaps he would argue that's justifiable and would be based on facts, but it's still an effort to impact the investigation.

5. The attacks on Mueller's team

There are almost too many to list here, but Trump has regularly attacked figures involved in the Mueller probe, up to and including the man overseeing it, Deputy Attorney General Rod J. Rosenstein, and Mueller's lawyers.

Every person has the right to defend themselves publicly, but as the Starr Report showed, a president's misleading public statements can be used against him. And maliciously attacking the credibility of investigators could conceivably play into this.

With the term whirling around Washington, a former federal prosecutor explains what to know about the criminal charge of obstruction of justice. (Jenny Starrs/The Washington Post)

Carol D. Leonnig contributed to this report.