In short, Hillary couldn’t beat Trump with the political dirt she secretly purchased during the campaign, so she tried to cripple his presidency with help from an overwhelmingly anti-Trump media. Framing Trump as some sort of modern-day KGB plant was an easy sell, since the pro-Democrat media were also searching for a scapegoat to rationalize the crushing defeat of their shared liberal agenda at the polls.
The irony is, it may have in fact been Hillary who came closer to colluding with the Russians in smearing Trump as a Russian traitor than anything Trump did in trying to beat Hillary. The information in the dossier she bought for millions came from Russian intelligence sources, and her lawyers brokered the deal with a Kremlin-tied lobbyist. When it failed to stop Trump, the Russia paymaster turned into the Russia spinmeister.
Now we really know “What Happened.”