President Trump and Russian President Vladimir Putin at their July meeting in Helsinki. (Pablo Martinez Monsivais/AP)

Special counsel Robert S. Mueller III’s mandate is, in its most basic form, clear. He was appointed to “investigate any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump.” If other matters arose from that work, he was authorized to look into those, as well.

From an investigatory perspective, that’s pretty straightforward. From a legal standpoint, it’s a bit trickier, given that contacts or coordination may not necessarily be illegal. From a political standpoint, it’s a complete minefield.

Trump has centered the debate over Mueller’s probe on the word “collusion,” a descriptor that is hopelessly — but, for Trump, usefully — vague. When we asked Post readers what would constitute collusion with Russia by Trump’s campaign, the responses were all over the map. A plurality of Trump supporters said that collusion meant Trump himself conspiring with a Russian agent; Trump opponents said it included a senior campaign staffer knowing about Russia’s effort to interfere with the election without the staffer trying to intervene.

As of writing, Mueller’s investigation is not complete (though that may change shortly). Through his publicly available indictments and news reporting about the Russia probe, we have a broad sense of where there was or may have been “coordination between the Russian government and individuals associated with the campaign of President Donald Trump,” as Mueller’s mandate reads. But in each case, there are gaps or murkiness that prevent the drawing of a straight line between Trump himself and Russian efforts.

Consider, for example, the infamous meeting at Trump Tower on June 9, 2016. We can distill that event down to a few core actors: Aras Agalarov, a Russian developer linked to Russian President Vladimir Putin; Rob Goldstone, a music promoter who represents Agalarov’s son; Donald Trump Jr.; Trump’s then-campaign chairman, Paul Manafort; and Jared Kushner, Trump’s son-in-law.

We know that Goldstone told Trump Jr. that the Russians had dirt on Hillary Clinton, which they wanted to share as part of a Russian effort to aid Trump’s campaign. So let’s draw a bright red line between Goldstone and Trump Jr. Goldstone was acting on behalf of Agalarov — but in a book, Goldstone claims that the specific enticement was something he came up with to sell the meeting to Trump Jr. It’s not clear, then, that Agalarov told Goldstone that the meeting was part of a Russian effort to aid Trump. We make that a dashed red line. Similarly, we don’t then know whether Agalarov had actual information about the interference effort from the Russian government — another dashed red line.

And while Trump Jr. clearly told Manafort and Kushner the reason for the meeting, Trump himself claims he didn’t know it was happening. Another dashed line. We get a diagram that looks like this.


(Philip Bump/The Washington Post)

Tantalizing — but with a lot of gaps.

Consider another set of interactions, between Manafort and his longtime aide Konstantin Kilimnik, who is believed to have ties to Russian intelligence. Manafort was in contact with Kilimnik multiple times during the campaign, including to see whether a former business client of Manafort’s named Oleg Deripaska might want a private briefing on how the campaign was progressing. At another point, he apparently shared campaign polling data with Kilimnik.

But why? To aid the Russian effort? Did Kilimnik even have a link to the Russian government? Did anyone on the campaign besides Manafort (and his deputy, Rick Gates) even know about the data being shared? The links between this meeting and Trump, and between Kilimnik and the Russian government, are sufficiently vague that they get dashed gray lines. The offer of a campaign briefing was made — but there’s no indication that it was related to the interference effort. Solid gray line.


(Philip Bump/The Washington Post)

Again: gaps. But we have a rough visual language for evaluating the contacts between people possibly linked to the Russian government and people affiliated with the Trump campaign.

The entire investigation into possible coordination originated with a campaign adviser, George Papadopoulos, being told by a London-based professor, Joseph Mifsud, that Russia had emails incriminating Clinton. He was told this in April 2016 and later shared it with an Australian diplomat who tipped off the FBI in July 2016, after WikiLeaks started dumping stolen information.

So Papadopoulos appears to have been told about an actual element of the interference effort, the hacking of material from Clinton’s campaign chairman and/or the Democratic National Committee, suggesting that Mifsud knew about some part of Russia’s broader effort. But it’s not clear Papadopoulos passed that on to campaign adviser Stephen Miller after being told by Mifsud — or that the information then made its way to Trump.

Papadopoulos also was in repeated contact with an official named Ivan Timofeev about possibly having Trump and Putin meet. He reported on those contacts to campaign adviser Sam Clovis, but it’s not clear that this included discussions of the interference effort or stolen material.


(Philip Bump/The Washington Post)

That material was allegedly stolen by the main Russian intelligence directorate, or GRU, according to Mueller. It was then passed to WikiLeaks, which published the bulk of it.

Longtime Trump adviser Roger Stone repeatedly indicated that he had advanced awareness of what WikiLeaks was doing, including, according to Trump’s former personal attorney Michael Cohen, giving Trump a heads-up in July 2016 that the first batch of documents was coming.

Stone appears to have had two possible connections to WikiLeaks. One was through a writer named Jerome Corsi who was in contact with another London-based writer named Ted Malloch. The other conduit was radio host Randy Credico, who interviewed WikiLeaks founder Julian Assange in 2016.

It’s not actually clear, though, how much Malloch and Credico actually told Stone, if anything, and how much was Stone blustering and guessing. It’s not clear what he told Trump or when. And there’s been no indication that Stone knew that the WikiLeaks material was part of an interference effort. Stone publicly distanced Russia from the hacking in a post at Breitbart, earning a private thank-you from one of the alleged Russian hackers who identified himself as “Guccifer 2.0.”


(Philip Bump/The Washington Post)

Then there was Carter Page, another campaign adviser. While in Moscow in July 2016, he had a conversation with a Russian official named Arkady Dvorkovich. Dvorkovich, Page said in an email to Trump adviser J.D. Gordon, “expressed strong support for Mr. Trump.”

Did Dvorkovich say more than that? Was he aware of the interference effort? Did Page relay anything more detailed to Gordon? There’s no evidence that he did — or that Trump was aware of this contact.


(Philip Bump/The Washington Post)

Gordon played another role, later in the campaign. As Election Day neared, he socialized with a woman named Maria Butina who last year admitted to working as an unregistered Russian agent. She was working with a Russian official named Alexander Torshin, trying to leverage the National Rifle Association’s close ties to Republican officials to build political relationships like the one she built with Gordon.

Again, though, Torshin and Butina have not been shown to have been aware of the interference effort — and, again, there’s no indication Trump knew about Gordon’s conversations with Butina. Or, really, any indication such information might have been useful to him.


(Philip Bump/The Washington Post)

Torshin had been trying to get a contact with the Trump campaign for some time. In May, he made two efforts to meet with the campaign, asking allies to send emails to set up a meeting for him. He eventually met with Trump Jr. — briefly, it seems — during a dinner associated with the NRA’s 2016 national convention in Louisville. There is no sign that this involved discussion of the interference effort or that Trump Jr. told Trump about the meeting.


(Philip Bump/The Washington Post)

As we’ve been walking through these, we’ve been detailing conversations that were less and less likely to have actually involved any direct coordination. Take Trump Jr.'s late-campaign interactions with WikiLeaks, in which the organization asked him to share links or to weigh in on certain issues. There’s no indication the contact went beyond that, or that Trump Jr. was aware that the WikiLeaks material was part of an effort to interfere with the election.

We’ll note here that, like Stone, Trump Jr. should have been aware that it probably was, because it was already well established in 2016 that Russia was the likely source for the material and, in Trump Jr.'s case, because he’d received an email in June from Goldstone describing a deliberate effort by Russia to aid Trump. But those pieces may fit together more obviously in hindsight.

Trump Jr. informed some on the campaign about his contacts with WikiLeaks, but it’s not clear that his father knew.


(Philip Bump/The Washington Post)

Multiple campaign staffers, including then-Sen. Jeff Sessions (R-Ala.) and Kushner, met with the Russian ambassador, Sergey Kislyak. A contact between the Russian government and the Trump campaign that falls within Mueller’s mandate, sure. But probably not part of a back-channel effort to collude — and it’s again not clear what Trump might have known about the meetings.


(Philip Bump/The Washington Post)

One of the more scrutinized revelations that emerged during the Mueller investigation was that Trump’s attorney Cohen had been involved with a proposal to build a new Trump development in Moscow for at least the first half of 2016. Trump himself was looped into those conversations, which at one point involved Cohen reaching out to Putin’s office directly. He ended up speaking with an aide to Putin’s personal spokesperson.


(Philip Bump/The Washington Post)

There are a number of other direct and indirect contacts between Cohen and the Russians related to that project: bankers, a former intelligence official who was tasked with pushing it forward, officials putting together an economic summit to which he was invited. But none of it was clearly an effort to engage Cohen in Russia’s attempts to swing the 2016 election.

There is no scenario that we know of where there is a bright red line that can be drawn from Putin through intermediaries to Trump. There are plenty of points of contact, many roads between the two, but none that definitively and universally address the question Americans are most eager to know the answer to: Did collusion exist?

But, then, proving collusion was never actually Mueller’s mandate.