President Trump (Jabin Botsford/The Washington Post)

President Trump’s inability to extend a better-than-usual public moment has been the telltale sign of his campaign and presidency. All those “pivots” and glimpses of “normalcy” have been swiftly followed by a reversion to his lifelong behavior — undisciplined antagonism, self-pitying and just plain lying. So it was on Thursday, less than 24 hours after the horrific shooting at the GOP congressional baseball team practice in Alexandria — and a much-praised speech and appropriate evening hospital visit to sit with injured House Majority Whip Steve Scalise (R-La.) — that Trump reverted to attacking the special counsel, railed at Hillary Clinton (!) and, frankly, seemed once again unglued. The Post reported:

A defiant Trump at multiple points Thursday expressed his frustration with [the special counsel’s widening investigation], tweeting that he is the subject of “the single greatest WITCH HUNT in American political history,” and one that he said is being led by “some very bad and conflicted people.”

Trump, who only a day earlier had called for a more civil tone in Washington after a shooting at a Republican congressional baseball practice in Alexandria, Va., fired off several more tweets in the afternoon voicing disbelief that he was under scrutiny while his “crooked” Democratic opponent in last year’s election, Hillary Clinton, escaped prosecution in relation to her use of a private email server while secretary of state.

Trump may want to stay away from the topic of “pols who endanger national security by failing to take precautions against the Russians.” More important, each accusatory tweet sounds like one more instance in a pattern of trying to stop or divert investigators and lean on potential witnesses. Meanwhile, Trump’s surrogates launched ham-handed attacks on special counsel Robert S. Mueller III (which virtually no elected Republican thinks are warranted).

The special counsel overseeing the investigation into Russia's role in the 2016 election is interviewing senior intelligence officials to determine whether President Trump attempted to obstruct justice, officials said. (Patrick Martin,McKenna Ewen/The Washington Post)

On Friday morning, the tweetstorm continued. He declared, “I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt.” In a spasm of anger — or is it panic? — he insisted, “After 7 months of investigations & committee hearings about my ‘collusion with the Russians,’ nobody has been able to show any proof. Sad!”

You can almost hear Trump champing at the bit, ready to fire Mueller or perhaps Deputy Attorney General Rod J. Rosenstein just as he did former FBI director James B. Comey, over the protests of some saner members of his family and staff. (Trump seems not to recall that this backfired, prompting Comey to step forward with his memos memorializing conversations with the president and to lay out the case for obstruction.)

Trump’s inability to restrain himself under pressure is nothing new. We saw him dig deeper and deeper when it came to attacking the Hispanic judge in the Trump University case or insulting the Gold Star family of Army Capt. Humayun Khan. Now, however, his obsessive attacks take on legal meaning — perhaps instances of obstruction of justice in and of themselves, or, at the very least, powerful evidence that Trump would have tried just about anything to throw the FBI off the trail.

Trump likely will become more unhinged as headlines dog him day after day, a parade of witnesses troop in to talk to the special counsel and the investigation metastasizes. First we had collusion allegations, then obstruction allegations and now reportedly financial crimes allegedly committed by multiple individuals, including Jared Kushner. We don’t know whether these activities, not the purported collusion with the Russians during the campaign, were the source of Trump — and Kushner’s — angst about letting Comey proceed with his investigation. At any rate, the noose will tighten, especially as the prosecutorial team demands financial records that Trump has so far concealed from view. If ordered to comply with document subpoenas, will he comply as Richard Nixon was obliged to do after the Supreme Court’s ruling on the tapes — or will he defy the order of one of those so-called judges and finally take his ball and stomp off for good?