Washington (CNN) President Donald Trump sent this tweet on Thursday morning: "Workers of firm involved with the discredited and Fake Dossier take the 5th. Who paid for it, Russia, the FBI or the Dems (or all)?"

Workers of firm involved with the discredited and Fake Dossier take the 5th. Who paid for it, Russia, the FBI or the Dems (or all)? — Donald J. Trump (@realDonaldTrump) October 19, 2017

This is, of course, somewhat common fare by this point in the arc of Trump's presidency. Faced this week with storylines he doesn't like -- questions about the Niger attack , controversy over a phone call he placed to the widow of one of the soldiers lost in that attack, Attorney General Jeff Sessions on Capitol Hill facing questions about Russian meddling in the election -- he aims to change the subject via his Twitter feed. And he often does so by lobbing out a conspiracy theory with only the loosest ties to the factual world.

But even by Trump standards, this morning's tweet is somewhat remarkable. He is suggesting that a dossier prepared by a former member of British intelligence has not only been totally discredited (it hasn't -- more on that in a minute) but that it might have been funded by some combination of Russia, the Democratic Party and, wait for it, the FBI!

Let's start with the facts.

At issue is a dossier prepared by Christopher Steele, a former British spy, which details explosive allegations about potential ties between Trump's campaign and Russia. The dossier's more salacious elements regarding Trump have drawn most of the attention -- and remain totally unproven. But it appears as though US intelligence officials do take some chunk of what Steele found quite seriously.

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