Yeah, intelligence service of both(and more) countries probably do that kinda of stuff on a regular basis, that's why they exist, but I don't think that had hardly any effect. "Russians, Russians", "Trump is a puppet of Putin" etc was a convenient scapegoat for losing the election. But problem of democrats was not Russians, but the fact that half of the country was ok with voting for Trump. And split was there long before and just growing with time, but Americans are doing great job splitting up themselves. Like with anti-sanders higher up demparty struggle. Both sides are now so politicized they are ready to bend reality and view everything through hate to the opponent.