Mueller apparently disagrees with you, seeing as he just indicted 13 Russians for doing that.There is no law against Russians supporting.
You seem to be unable to separate the two aspects of the investigation:Do you even know what collusion means?
"secret or illegal cooperation or conspiracy, especially in order to cheat or deceive others."
If Trump has some secret knowledge of illegal cooperation to deceive or cheat the election, I will speak in the chorus to call for, not only impeachment, but prison. But so far, there is NO EVIDENCE of that charge. If there is, show me. Bring forth the facts, don't tell me "we know" because we don't know. You speculate. Period.
1) To determine if and how Russia interfered in the 2016 election.
This has been proven beyond doubt. It has also been proven that Trump was the primary beneficiary of their influence campaign.
2) To determine if the Trump campaign colluded with the Russians.
This has not been proven. I believe there is evidence, but it might not turn out to be enough, or conclusive, or even illegal.
Now, reread the posts with this in mind. I have only claimed that (1) has been proven. You still expressed doubt that the Russians supported Trump, which at this point, is a fact that has been established by the FBI, the CIA, the NSA, and the special counsel.