Yes he did win a close election through gerrymandered districts that go against popular opinion. It is the system that we have and he won even though he lost the popular vote by 2 million votes.
And, what do you make of the independent investigation then? You are right that there is no evidence of collusion out in the open. But what we do know is that there is a lot of smoke, and if proven true, it is all very treasonous in nature.