When President Donald Trump fired FBI Director James Comey early in May, he said at the time that he'd made the call because of the bureau chief's (mis)handling of the probe of Hillary Clinton's use of a private email server while she'd been secretary of state. In other words, he wanted people to believe that he fired him out of the blue, after having earlier decided to keep him on, for something that had happened 10 months prior.

No rational soul alive actually believed Trump's explanation, of course.

Just a couple of days after Trump gave Comey the boot, the president, in an interview with NBC News, acknowledged that he'd had Russia on his mind when he sent the FBI chief his walking papers. Specifically, he said:

"When I decided to just do it, I said to myself, I said, 'you know, this Russia thing, with Trump and Russia, is a made-up story.'

"It's an excuse by the Democrats for having lost an election that they should have won."

That he'd been thinking of Russia rang more true, at least for most folks.

Now comes news that Robert S. Mueller III, the special counsel appointed in the wake of Comey's firing, has been taking a close look at a draft of a letter Trump composed in advance of his axing of the FBI chief. Mueller, of course, has been probing Russia's meddling into our presidential election last year, any links between those efforts and the Trump campaign, and related matters.

His examination of the letter, reportedly composed by Trump and top adviser Stephen Miller, prompts one to wonder if Mueller, himself a former FBI chief, might be building a case against Trump for obstruction of justice.

According to reports late last week, Trump became increasingly agitated over Comey's refusal to state publicly and for the record that he wasn't investigating the president. Though the director had assured Trump on three occasions that he personally wasn't a focus of the probe, that apparently wasn't good enough for the former reality TV star. He wanted more.

But when Comey didn't deliver, Trump could take no more and ended his tenure.

The Trump-Miller document, as described in reports, was fully four pages long. And it rambled, ranted, and may, in the end, prove to be yet another thorn in the president's side.

So much of Trump's diminution of his own standing as president has been of his own hand. His unceasing posts to Twitter. His needless provocations of those who ought to be his allies in Congress. His disjointed, ranting rallies for the faithful, the dwindling core of supporters who continue to stand by their man through thin and thin.

It's all a part of the same sorry tale: Trump's lack of discipline continues to spell trouble. As though firing Comey hadn't been bad enough. But then came the TV interview during which he admitted that he'd been thinking of Russia when tossing the director overboard. And now the draft of the letter, described by some who've seen it as a "screed."

Trump had once seen the Russia probe as a cloud over the White House that he'd hoped would eventually blow over. Not only is that not happening, the cloud keeps on growing ever darker.