Probably gonna need to define what constitutes a free and fair election because that kind sounds like accepting the results as long as you end up winning....which I previously criticized Trump for saying.
Unless it’s proven that Russians or/or a big conspiracy of separate state election officials actually changed votes from Hill to DTJ in sufficient numbers to change a sufficient number of electoral votes to install Trump over Hill, the election was free and fair.
If Russia and/or Trump and/or others uses twitter bots, social media analytics, propoganda, whatever to dupe enough Americans to vote for Trump instead of Hill, that’s a free and fair election and a inherent risk of an uninformed or ill-informed electorate....you deserve the government you are duped into electing. Of course, if the electorate determines they feel angry enough about being duped, impeachment proceedings would be appropriate. “High crimes and misdemeanors” worthy of removal is pretty much whatever the electorate through it’s elected reps determine it is....doesn’t really require a violation of the criminal statutes to qualify as such.