“Gore lost after the US House impeached Bill Clinton. Gore might have won, if the Republican base was not energized by the Impeachment process of Bill Clinton.”
Gore lost by a famously slim margin, of course. Kind of hard to definitively judge the effect of the impeachment on public opinion and voter turnouts just based on that. It might be just as true that it energized both sides, resulting in a such a close race.
Remember also that the Congressional elections happened at the same time, and Republicans lost seats in both chambers. I don’t think that is the wave of enthusiasm we are hoping for.
In the House in the first election after impeachment (2000), Republicans won 233 seats, Democrats won 211 seats.