Your claim has actually been proven to be false. Trump was already impeached by the Democrats and they have not only won the Presidency but also gained control of the Senate.
A second impeachment of Trump will completely destroy him.
It's impossible to replay time with just one variable changed, so we will never know the other "what if" scenarios. However, to say that impeaching Trump was what caused the election victory is to commit the "post hoc ergo proctor hoc" fallacy.
In my opinion, had the pandemic not come along, Trump would have sailed to an easy win.
That's not an assertion that can be proven, for exactly the reason that I gave in my first paragraph, but we can at least investigate the issue somewhat scientifically. When pollsters talked to voters what was important to them, not many said anything that could remotely have been interpreted as "being impeached" or "adjusting foreign policy to dig dirt on political opponents."
I've been reading some more of the in depth articles about events of last week, and they really have influenced me. What he did really deserves removal from office, even if it is only one day. i.e. even if they couldn't manage to remove him before January 19th, he really ought to be removed from office. What he did was very, very, bad. Really bad. Not Hitler level bad, but more on the scale of Mussolini level bad. Maybe it would be a good thing to impeach again even if there aren't the votes for removal. And maybe I don't care if the Democrats are hurt politically in the event that they fail.
What needs to happen is for people to vote based on reality, not on who is on their team. I'm not sure you can get there from here, but you can't do it by deciding not to do the right thing because it's politically expedient not to. If the Democrats lose ground as a result of doing the right thing, it's a sign that people don't trust them, either, and think that they are grandstanding. Maybe they are right.
I feel that there is a real dearth of principled leadership in America right now. A stand on principle might be what the country needs, and if people judge that stand to be insincere, so be it.