© CQ-Roll Call/Josh Roberts/Reuters/Win McNamee/Getty Images/KJN
But people with direct knowledge of the situation say the premise of that speculation is false: It's highly unlikely that these associates possess proof of collusion and are singing about it to Mueller. "It's wishful thinking by Trump haters," said a former Trump campaign official who has been the subject of investigation.
Mueller has obtained guilty pleas from four ex-Trump advisers - Michael Flynn, George Papadopoulos, Paul Manafort and Rick Gates - for crimes unrelated to election espionage. Facing the prospect of a lengthy prison sentence, each had strong incentives to turn on the president.
So, too, do other Trump associates reportedly caught in Mueller's crosshairs - Carter Page, Roger Stone and the president's former lawyer, Michael Cohen, who has pleaded guilty to crimes referred by Mueller's office to federal attorneys in Manhattan for prosecution.
Mueller has clamped down on leaks from his office, so it is hard to determine exactly what he has extracted from the witnesses. Nevertheless, substantial information gleaned from various sources by RealClearInvestigations and other news outlets suggests that Trump's former associates have not provided the smoking gun of collusion. As emboldened Democrats promise to step up their own Russia investigations when they take over the House in January, here is what we know so far about each case.
Michael Flynn
Former national security adviser Flynn, who pleaded guilty in 2017 to lying about a post-election conversation he had with the Russian ambassador, is not providing evidence against Trump, insisted a family insider close to the matter: "That's all bullshit, media created and driven."
"I find it funny how the left thinks he's been 'cooperating' with Mueller this whole time, yet he's spent the majority of time in Rhode Island since the plea deal in 2017," said the source, adding that Flynn has traveled infrequently to Washington, where the Special Counsel's office is based, since negotiating the legal agreement last December.
Flynn and his family are from Middletown, R.I. The relative, who spoke on the condition of anonymity, also reported that Flynn has met with his own representatives infrequently. "He has met his lawyers every other month this year," the source said, "and only for a few hours at a time."
Flynn's sentencing is now set for Dec. 18 - Mueller had previously delayed it several times, signaling that he was not getting the information he had hoped for. The sentencing will effectively mark an end to Flynn's cooperation.
A retired U.S. Army lieutenant general, Flynn publicly stated last December his decision to cop a plea to the single-count process crime was "made in the best interests of my family." He did not elaborate, but the family insider explained that fighting the charge "would have bankrupted us."
"The justice system, especially in Washington, is all about who has more money and resources," the family member said. "Clearly, our military family had no chance against the weight of the federal government. It makes me sick every day thinking about it," Flynn's relative added, while suggesting Flynn was railroaded.
In fact, former FBI Director James Comey has said Flynn provided truthful answers and wasn't intentionally misleading investigators on Jan. 24, 2017, when he was questioned about his contacts with the Russian ambassador during the presidential transition.
In a March 15, 2017, closed-door briefing before the Senate Judiciary Committee, the then-bureau director swore the two FBI agents who originally interviewed Flynn "saw nothing that led them to believe [he was] lying," according to committee documents. This assessment suddenly changed after Comey was fired by Trump and Mueller took over the Russia probe two months later.
George Papadopoulos
Another witness who struck a plea deal with Mueller - George Papadopoulos - has not flipped on Trump, either.
The former Trump adviser was arrested in July 2017 and pleaded guilty that October to making false statements to the FBI. The case revolved around whether Papadopoulos suspected a Russian connection to Joseph Mifsud, a Maltese academic who allegedly knew as early as March 2016 that Russians possessed "dirt" on then-candidate Hillary Clinton in the form of "thousands of emails." Initially he told the FBI he did not; in his guilty plea he said he did. He also told agents he met Mifsud before joining the Trump camp, when in fact he met him after working on the campaign.
Washington pundits said that Papadopoulos, a campaign volunteer with no title or portfolio, would most certainly turn on Trump to avoid a stiff sentence. Famed Watergate reporter Carl Bernstein even suggested his revelations could outline a scandal worse than Watergate.
Papadopoulos said he handed over all his emails, text messages and other communications with the Trump campaign to Mueller's investigators. In the end, he didn't provide any information of value, according to documents Mueller filed in court, and Mueller cut him loose in September. He received a 14-day sentence.
At the sentencing hearing, Mueller prosecutor Andrew Goldstein said information Papadopoulos provided didn't amount to much. "It was at best begrudging efforts to cooperate and we don't think they were substantial or significant in any regard," he said.
Papadopoulos now says he was set up by FBI informants and that his interactions with Russian-tied individuals were innocent, and certainly not the sinister dealings portrayed by the media.
He explained he lied about a meeting with one of the contacts because he wanted to get a job in the administration, and that he was not to trying to hide any illicit collusion with Russia.
Paul Manafort
Former Trump campaign chairman Paul Manafort has been called Mueller's "most significant cooperating witness" to date. But this too may be overstated.
Manafort struck his own cooperation deal with Mueller in September, after being convicted on charges of bank and tax fraud unrelated to the campaign. The plea agreement let him avoid a second trial in Washington on related charges.
It's still unclear if Manafort, who reportedly has been meeting regularly with Mueller's prosecutors while incarcerated, is providing information about the Trump campaign and Russia or about other matters. ABC News reported Friday that discussions have broken down as Manafort has offered prosecutors few leads on the Russia front and is not providing the level of cooperation promised under his plea agreement. Manafort's sentencing hearing is set for Dec. 12.
Still, pundits surmise he may be providing damaging information on the president and Donald Trump Jr., who hosted a June 2016 meeting at Trump Tower after being solicited by a group of Russians who promised dirt on Hillary Clinton.
Congressional committees have found no evidence of collusion in the meeting, which they concluded was perfectly legal and resulted in no information provided on Clinton. They also noted that the solicitation itself suggests that there had been no previous contact between the Russian government and the Trump campaign, and that the absence of a communications channel, if anything, shows a lack of collusion.
Nevertheless, Fordham Law School professor Jed Shugerman is among those speculating that Manafort has been providing "big leads" to Mueller about Russia "collusion." So is Seth Waxman, a former Clinton appointed-Justice Department official, who has claimed Mueller must "believe he has very valuable information."
Duke University Law School professor Samuel Buell, a former federal prosecutor, has argued that Mueller wouldn't offer Manafort such leniency unless he provided "substantial assistance" in the prosecution of others higher up. "He's not going to get that deal unless he can help Mueller make a case against one or more people," he said recently.
The White House has said it's not concerned with Manafort's plea deal, arguing that he, like all the others, cannot offer evidence of collusion because it doesn't exist. Some former federal prosecutors question Manafort's usefulness to Mueller for a different reason: His former right-hand man, who had made his own deal with Mueller seven months before Manafort, would have already given any damning information to the special counsel.
Rick Gates
Manafort's longtime business partner Rick Gates pleaded guilty last February to conspiracy and false statements unrelated to the Trump campaign.
Gates served as Trump's deputy campaign chairman under Manafort. And though Manafort left the campaign in August 2016, Gates stayed on through the election and subsequently had a key role in the presidential transition and inauguration.
Gates has actively cooperated with Mueller; his recent testimony helped prosecutors secure the guilty verdicts against Manafort.
Despite his thorough cooperation, Gates did not provide information that would have allowed Mueller to bring conspiracy charges against Manafort in the Russia case. Gates reportedly told Mueller the only serious overtures he heard from foreign nationals to help the campaign came from Israeli, not Russian, sources.
"I find it hard to believe Mueller sees Manafort as the key to making a case on Trump when Mueller has had Gates - Manafort's partner - as a cooperator for months," said former federal prosecutor Andrew C. McCarthy. "You have to figure Gates knows whatever Manafort knows about collusion."
Yet since Gates began cooperating with Mueller's office, the special counsel has filed no charges implicating Trump or even Manafort in any Russian conspiracy. He has even filed charges against Russian nationals without implicating Trump or his campaign.
Still, Gates is not done cooperating. He has not yet been sentenced and faces up to 10 years in prison if he doesn't fully satisfy the terms of his plea agreement.
It's also possible Mueller has cultivated other cooperators unknown to the public whose plea deals are still under seal. Mueller's office declined comment.
Michael Cohen
Mueller's prosecutors also have met with Michael Cohen, Trump's former personal lawyer, but Mueller handed over the case to others in the Justice Department, suggesting Cohen offered little of value in the Russia investigation.
Cohen pleaded guilty in New York in August to tax evasion, bank fraud and violations of campaign finance laws. That separate investigation, unrelated to the Trump campaign or Trump's real estate empire, is headed by the U.S. attorney's office in Manhattan.
Cohen's lawyer, Lanny Davis, said his client has "no cooperation agreement" with Mueller, which indicates the special counsel doubts Cohen has anything productive to say about Russian collusion. Materials seized from or provided by Cohen played a large role in the Wall Street Journal's recent story about Trump's use of third parties to buy the silence of at least two women he had slept with. It is not clear if the president's actions violated campaign finance laws.
Roger Stone
Then there is longtime Trump confidant Roger Stone, who is currently under active investigation by Mueller's office. Investigators want to know if he had any insider information about the release of stolen Democratic emails to WikiLeaks during the 2016 campaign.
Stone insists Mueller is trying to "frame me for some extraneous crime."
"The FBI tried to question my cleaning lady and FBI agents have been seen sifting through my garbage," Stone said at a recent appearance in West Palm Beach, Fla. "Here's what I can tell you: They will find no evidence of Russian collusion. ... They will find no evidence of WikiLeaks collaboration."
Stone vowed he would not cooperate with Mueller's team against Trump.
Though Trump aides have, one by one, cut plea deals with Mueller, none of their guilty pleas has had anything to do with Russian hacking or interference in the 2016 election, which is what Mueller is supposed to be investigating. Flynn, Papadopoulos, Manafort and Gates all pleaded guilty to other crimes.
But Mueller is still investigating the Russia "collusion" theory, while spending about $1 million a month to make sure no stone is left unturned. And with all these Trump associates talking, it would appear the noose is growing tighter around Trump -- or so goes the conventional wisdom inside the Beltway.
It's an assumption unsupported by facts, however. The evidence so far indicates that their cooperation has not been anywhere near as devastating to Trump as his detractors have portrayed it.
One irony is that the one person who was put under FBI surveillance the longest for alleged illicit Russian ties - former Trump adviser Carter Page -- has not been indicted.
Page, who also has been subjected to multiple interviews with FBI agents and appearances before Mueller's grand jury, has denied any role in Russian interference in the campaign. He called the investigation a "witch hunt" in a recent RealClearInvestigations interview, while adding that Mueller has not told him to expect an indictment.
Comment: A million dollars per month...the cost of finding nothing - over and over again.