We now know for sure, thanks to the stage managed revelation (by DoJ through Senator Graham) of Strzok's notes critiquing the NYT coverage, that Strzok--and presumably everyone else in his FBI orbit--had come to that conclusion no later than mid-February, 2017. Well before Team Mueller was set up.
Who else thinks Rod Rosenstein has a LOT to answer for? The reason he has a lot to answer for is in plain sight for anyone who reads Strzok's notes. Rosenstein claimed that the witchhunt was simply a continuation of Crossfire Hurricane, the investigation of "four Americans" associated with the Trump campaign that the FBI ginned up in summer of 2016. But Strzok makes it clear that not only was Trump himself clear of such claims, but so, too, were all Trump associates. Even Politico gets that--or has been forced to admit that--finally. With the Carter Page FISA still running--and yet to be renewed two more times!--Strzok wrote re claims being pushed by the NYT:
“We have not seen evidence of any officials associated with the Trump team in contact with IOs [intelligence officers]. We are unaware of ANY Trump advisors engaging in conversations with Russian intelligence officials.”
In other words, the stuff being peddled as investigative gold by the NYT was, in fact, the purest propagandistic horsesh*t.
Here's how Politico soft peddles Strzok's quite categorical statements:
The documents suggest that even as press reports began to describe connections between Americans in Trump’s orbit and figures in Russia’s shadowy intelligence services, the FBI had gathered little, if any, evidence that such ties existed.
"Suggest." As if one needs to somehow parse Strzok's words to ascertain just what he might be trying to say. Instead, Politico tries to staunch the mortal wound that Strzok's notes are to the Russia Hoax by blaming ... The Orange Man:
Trump supercharged the investigation, however, in May 2017 when he abruptly fired FBI Director James Comey and invited senior Russian officials to the Oval Office. Comey went on to provide internal notes, through an intermediary, to The New York Times that described his growing concerns about Trump’s posture toward the Russia probe. Days later, the Justice Department appointed Mueller to take over the Russia investigation, which continued for two more years.
Problem: Rosenstein appointed Mueller to "take over [a] Russian investigation" which Strzok himself had admitted months previously in categorical terms had no predication. How does firing the FBI Director--based on a justificatory memo that Rosenstein himself wrote--justify continuing an investigation that had no predication? Does the President of the United States inviting with "senior Russian officials" to the Oval Office justify opening an investigation? Rosenstein nowhere suggests that as a basis for any investigation, but for the sake of argument, exactly how would one articulate that as predication for an investigation? It doesn't pass the laugh test.
This, now, is what the NeverTrumps are reduced to.