The Steele dossier, that collection of incendiary allegations against Donald Trump compiled for the Hillary Clinton campaign by the former British spy Christopher Steele, was already widely discredited before the release of the Mueller report. Now, the report has hammered a few additional nails in the dossier's coffin.

Mueller's work "underscored what had grown clearer for months," the New York Times reported recently, "that while many Trump aides had welcomed contacts with the Russians, some of the most sensational claims in the dossier appeared to be false, and others were impossible to prove." Mueller, the Times noted, included a number of references to the dossier's allegations, "but no overall assessment of why so much did not check out."

The dossier alleged a massive, long-running conspiracy between the Trump campaign and Russia, complete with money, politics, and sex. Among its most sensational charges:



The allegation that in 2013, in a Moscow hotel room, Trump watched as prostitutes performed a "golden showers" show on a bed in which former President Barack Obama had once slept, while Russian spy cameras recorded the whole thing.

The allegation that the head of Rosneft, the giant Russian state-owned oil and gas company, offered low-level Trump foreign policy adviser Carter Page billions of dollars in return for ending U.S. sanctions against Russia.

The allegation that in August 2016 Trump fixer Michael Cohen met Russian officials in Prague to arrange secret payments to Russian hackers who attacked the Clinton campaign.

The allegation that short-term Trump campaign chairman Paul Manafort managed a "well-developed conspiracy of co-operation between [the campaign] and the Russian leadership," including "an intelligence exchange [that] had been running between them for at least eight years," and that Manafort was succeeded in that job by Cohen after Manafort left the campaign.

None of Steele's charges were confirmed in the Mueller report. Some were specifically debunked. Others were ignored. In short, the report's release was not good news for Christopher Steele.

In the wake of Mueller's findings, there are videos going around the internet of liberal media figures saying embarrassingly credulous things about the dossier. They even invented a new standard of evidence — "not proven untrue" — to justify believing it long after its main claims had been either discredited or were dying for lack of proof.

But that's just TV talk. What was remarkable about the dossier was that some Democrats in key positions in government — lawmakers who had access to the nation's deepest secrets — embraced the dossier and used its allegations against the president even though they knew, or should have known, there was no evidence to support them.

It can be difficult to remember how completely those Democrats embraced the dossier. But start more than two years ago, on March 20, 2017, when the House Intelligence Committee held a hearing entitled "Russian Active Measures Investigation," featuring testimony from FBI Director James Comey and National Security Agency chief Michael Rogers. Committee Democrats made the dossier a key part of their attacks on the president.

It began with Rep. Adam Schiff, D-Calif., who was the ranking Democrat at the time and is now the committee's chairman.

"According to Christopher Steele, a former British intelligence officer who is reportedly held in high regard by U.S. intelligence," Schiff began, as he detailed the dossier's unsupported Carter Page/Rosneft allegation.

And then: "Also according to Steele's Russian sources," Schiff said before outlining the dossier's unsupported allegation that Russia offered the Trump campaign documents damaging to Hillary Clinton.

And then: "According to Steele," Schiff said before recounting the dossier's unsupported allegation that Manafort managed the Trump-Russia conspiracy.

And then: "Is it a coincidence that the Russian gas company Rosneft sold a 19 percent share after former British intelligence officer Steele was told by Russian sources that Carter Page was offered fees on a deal of just that size?"

And then: "Is it a coincidence that Steele's Russian sources also affirmed that Russia had stolen documents hurtful to Secretary Clinton that it would utilize in exchange for pro Russian policies that would later come to pass?"

And that was just Schiff. Then came Democratic Indiana Rep. Andre Carson: "In fact, the dossier written by former MI6 agent Christopher Steele alleges that Trump agreed to sideline Russian intervention in Ukraine as a campaign issue which is effectively a priority for Vladimir Putin. There is a lot in the dossier that has yet to be proven, but, increasingly, as we will hear throughout the day, allegations are checking out. And this one seems to be as accurate as they come."

And then came Democratic California Rep. Jackie Speier: "In July of 2016, [Page] gives a graduation speech at the New Economic School, denies meeting with the Prime Minister. Christopher Steele in his dossier says he met with, again, Igor Sechin, offering a 19 percent interest in Rosneft. It becomes the biggest transfer of public property to private ownership."

And then came Texas Democratic Rep. Joaquin Castro who based his entire questioning on the dossier. Forgive the long quotation:

I want to take a moment to turn to the Christopher Steele dossier, which was first mentioned in the media just before the election and published in full by media outlets in January. My focus today is to explore how many claims within Steele's dossier are looking more and more likely as though they are accurate...



The reputation of the author, Christopher Steele, as a former accomplished British intelligence officer with a career built on following Russia, is important. This is not someone who doesn't know how to run a source and not someone without contacts.



The allegations it raises about President Trump's campaign aides' connections to Russians, when overlaid with known, established facts and timelines from the 2016 campaign, are very revealing. So let's begin...



The dossier definitely seems right on these points. A quid pro quo relationship seems to exist between the Trump campaign and Putin's Russia. A July 19, 2016, entry, for example, asserts that Russians were receiving intel from Trump's team on Russian oligarchs and their families in the United States.



An entry from June 20, 2016, states, quote, "Trump and his inner circle have accepted regular flow of intelligence from the Kremlin, including on his Democratic and other political rivals," unquote, which is something for something.



A July 30 entry likewise states that, quote, "a source close to the Trump campaign confirms regular exchange with the Kremlin has existed for at least 8 years, including intelligence fed back to Russia on oligarchs' activities in the United States."



And I know that my colleagues have touched upon this, but I think it is important, in the context of Christopher Steele's dossier, to bring it up again. So my question is, is it likely or plausible that the Russians might seek out Americans for Moscow's purposes?...



So the dossier states in an entry dated August 10, 2016, that a, quote, "Kremlin official involved in U.S. relations," unquote, suggests that Moscow might offer assistance to, quote, "sympathetic U.S. actors." Does this sound like a plausible tactic out of the Russian playbook? ...



Now, let's get even more specific. Among the U.S. actors this Kremlin official mentions are Carter Page and Michael Flynn, whom my colleagues have already discussed at length and which the dossier describes as, quote, "examples of successes" by the Kremlin official. We know Carter Page went to Moscow on July 7 to give a speech to the New Economic School. We are in possession of the slide deck from his speech there. And we know Carter Page obtained approval from the Trump campaign manager at the time, Corey Lewandowski, as reported in Politico, citing national security campaign official J.D. Gordon. Now, let me ask you another question with respect to somebody else. Is it correct that Igor Sechin, the president of Russian oil giant Rosneft, is a former member of Russian intelligence and a longtime aide and confidant to Vladimir Putin? ...



In an October 18, 2016, entry, the dossier states that, during Page's visit to Moscow, he met with Igor Sechin, offering, quote, "Page and Trump's associate the brokerage of up to 19 percent stake in Rosneft," with Page conferring that, quote, "if Trump were elected U.S. President, sanctions on Russia would be lifted." And although, fortunately, the White House hasn't been so naive as to unilaterally lift sanctions on Russia, it was widely reported that on January 27 of this year Rosneft sold a 19.5 percent stake in Rosneft in what Reuters calls, quote, "one of its biggest privatizations since the 1990s." Furthermore, Reuters reported that, quote, "public records show the ownership structure of the stake ultimately includes a Cayman Islands company whose beneficial owners cannot be traced." What a coincidence...



An entry from July 19, 2016, in the dossier states that a Trump associate knew that the Kremlin was using WikiLeaks in order to maintain, quote, "plausible deniability of its involvement." Three days after this entry, WikiLeaks carries out the Kremlin's wishes and publishes upwards of 20,000 stolen DNC emails and 8,000 associated email attachments. And the rest, as they say, is history.



Another entry, dated August 17, has Carter Page and a Russian associate discussing WikiLeaks publishing emails in order to swing Sanders supporters away from Clinton and to Trump. And, again, from a September 14 entry of the dossier: "Kremlin has further compromising material on Clinton in the form of emails and considers disseminating after parliamentary elections in late September." And on October 7, WikiLeaks publishes John Podesta's hacked emails. So the coincidences keep piling up.

Again, apologies for the long quotation. And things went on from there. Suffice it to say Democrats relied — heavily relied — on the dossier.

The problem was, proof of the dossier's claims was not forthcoming. Since the allegations were so spectacular, House Intelligence Committee Republicans were eager to know what the FBI was doing to verify the charges and whether the bureau had had any success. House GOP investigators — remember, they were in the majority at the time — issued request after request, and finally a subpoena, to the FBI for information about dossier verification efforts.

The bureau resisted for months. Finally, in November 2017, FBI and Justice Department officials admitted to the House that they had not been able to verify any of the dossier's substantive allegations.

That did not stop Schiff. "A lot of it has turned out to be true," he told the Wall Street Journal that November, after the FBI and DOJ briefings. "The biggest thing that I think people need to realize about the dossier is that Christopher Steele discovered that the Russians were embarked on a broad effort to help the Trump campaign before our own intelligence agencies came to the same conclusion. In the broadest outline of what he investigated, he proved more than prescient -- he proved accurate in terms of the Russian involvement and what their motivations were."

Thus was born the "broadly accurate" argument about the dossier. Maybe Steele got some details wrong, the argument went. But he got the big picture — collusion — right.

The problem was, months went by and still the U.S. government failed to corroborate the key accusations of the dossier. And as they failed to verify the dossier's particular charges, they also failed to verify the big picture. Out of sight, Mueller was failing, too. The special counsel interviewed Steele, and the Mueller report contains several references to Steele's reporting, although it never uses the word "dossier." And it confirmed nothing.

In the wake of the Mueller report, the question is not whether the dossier's charges were accurate, but why they were so wrong.

"How the dossier ended up loaded with dubious or exaggerated details remains uncertain," the New York Times reported, "but the document may be the result of a high-stakes game of telephone, in which rumors and hearsay were passed from source to source."

In retrospect, it was entirely wishful thinking to believe that a set of false allegations would somehow add up to a true big picture. And — this was clear from the start — the parts of the dossier that were accurate, like the fact that Carter Page traveled to Moscow in July 2016, were publicly reported at the time. Steele was a bad spy, but he could at least read the newspaper.

"Many of the validated assertions were already percolating in the press and Western intelligence agencies by the time Mr. Steele began compiling the dossier in the summer of 2016, including that Russia was trying to harm Mrs. Clinton," the Wall Street Journal recently reported.

Yet some of the Democrats who embraced the dossier years ago cannot seem to let it go. Now in charge of the House Intelligence Committee, Schiff has begun an all-new Trump-Russia investigation. As part of that, he has hired as an investigator former federal prosecutor Daniel Goldman, who just a few months ago said of the Steele dossier, "Nothing has been undermined thus far."

Another Intelligence Committee Democrat, Rep. Eric Swalwell of California, is now running for president and is still sticking up for the dossier. In a surreal exchange with Fox News' Martha MacCallum recently, Swalwell refused to find any fault with Steele's work.

"So it doesn't bother you," MacCallum asked, "that the Clinton campaign paid for a dossier to be put together by someone who had all kinds of ties to intelligence and put together something that turned out to be not necessarily factual?"

"Which part — which part of it hasn't been proved factual?" Swalwell responded.

"Well, Christopher Steele himself said it was not a finished work product — " MacCallum said.

"He doesn't say it wasn't factual, though," Swalwell said. "Which part was not proved factual?

"I mean, are you serious?" MacCallum asked.

"Yes," said Swalwell. "Tell me. I'm here. Tell me."

"So you think that the dossier — "

"Which part wasn't proved factual?"

"Okay, for one thing, Michael Cohen said he never went to Prague," MacCallum said. "Do you agree with that?"

"But which part has been proved to be not factual?" Swalwell said.

For the record, the Mueller report confirmed that Cohen never went to Prague. But in a larger sense, what is the lesson of the Swalwell interview? It is that some Democrats, even those who have access to highly classified intelligence and should know better, will give up the dossier only when, as gun lovers used to say, you pry their cold, dead fingers from it. Mueller report or no Mueller report, for some high-ranking Trump adversaries, the dossier lives on.

[Read more: Bob Woodward: Steele dossier appeared in draft of US intel assessment on Russian meddling]