If the Democrats win they will of course impeach Trump, but he can't be convicted without 2/3 of the Senate, and the Democrats have no chance of attaining that in the Senate. So the only chance of Trump being convicted while in office is if the Republicans turn on him, which I don't see happening without something very dramatic happening, like him attempting (and hopefully failing) to use nuclear weapons against Iran.
It may happen if enough republicans that want to stay afloat in the post-Trump era jump ship.
That era and the reckoning it will bring are coming, either now or in two years. The skillet is getting hotter day by day.
Trump doesn’t lose support of congresspeople except those on their way out. I don’t suspect nukes would change that equation, despite wreaking havoc on markets and humanity as a whole. The right wing propaganda machine would find an angle (probably fear of imminent attack) to make it seem prudent and even heroic. The reins have been shredded for a long time and the horse just keeps running wild, cheered on by those who would have any power to wrangle it.
At what point do constituents of Republican Senators have an influence over them?
Democratic and Republican voters are suffering equally.
At some point of rising costs of living, Republicans will break with dying Trump. They’ll blame his old age, and as Lindsey Graham put it “that Hitler shit.”
The can of whoop-ass the entire Republican party is about to take at every level on every ballot in every state might just be sufficient to alert some Senators that it's time to jump ship.
Obviously Republicans will win a large number of these elections, but even their victories will be a source of great alarm.