Until this month, the official story was that the FBI began their investigation of the Trump campaign in the Fall of 2016 after John McCain turned over the Steele Dossier to them. That timeline changed considerably with the revelation of Operation Crossfire Hurricane. Now it's being alleged that the FBI started investigating the Trump campaign much earlier.
Under the new timeline, Trump was under pressure from the Washington Post's endorsement panel to name some foreign policy advisors. The seasoned professionals were boycotting Trump so he had to settle for 3rd string back-benchers - people who had done business overseas. That set off alarms because at least two of these advisors "had ties with Russia".
Personally, I think it went back even further. Fairly early in 2016, Vladimir Putin was asked about Trump and said that he was clever (later translations say that he may only have called Trump colorful). Reporters demanded that Trump repudiate Putin, something that Trump's ego was not going to allow. Instead Trump accepted the compliment and said a couple of complimentary things about Putin. The pundits went crazy insisting that this somehow proved that Trump was Putin's puppet and that Trump was planning on overthrowing the US government and installing himself as an authoritarian leader.
Keep in mind that no one batted an eye when SoS Clinton met with Russia to reset relations or when POTUS Obama did his own reset. Or when Obama premised flexibility after the next election to the Russian ambassador over a hot mic Or when Obama made fun of Romney for calling Russia our biggest geo-political rival.
It's been pretty well established that the FBI and Justice Department were being run by Obama loyalists. I'm guessing that they were among those never-Trumpers who believed that Trump was colluding with Putin and looking for any excuse to open an investigation. Then Trump added some people with "ties to the Kremlin" to his advisors. Russia is pay-to-play. Anyone doing business there has ties with the Kremlin and these advisors had done nothing illegal. But that's all the excuse the FBI needed.
The New York Times article that broke the store about Operation Crossfire Hurricane admitted that the FBI considered quietly meeting with the Trump campaign. They decided against it. Why? Because they wanted to catch the Trump campaign doing something with the Russians.
In a Sunday morning news show, Comey claimed that it was all about Russia but why have FBI informants meet with the Trump campaign if things were as innocent as Comey claimed (and remember that Comey lied under oath to Congress about wiretapping so he is not a reliable source).
I think that rather than the FBI investigating the Russians and their connections with Trump, they were investigating Trump and his connections with Russia. The focus of the investigation was not Russia, it was Trump.
And that's why it's a scandal.