But you wouldn't expect me to agree with all of the points you're making here, of course.

It wasn't a party-line vote, a number of Republicans joined all Democrats in voting not to convict Clinton. But fair enough that it set a precedent. As for my opinion on the vote, I'm torn - it does seem clear enough that yes, he committed perjury, but on the other hand his extramarital escapades were for him and his wife to deal with and were, as you say, not relevant to the duties of his office, so it would've made little sense to remove him from office on that account.

The Trump bit reminds me of the French president Mitterrand back in the 80s who also got into a bit of a scandal when the press found out that he had fathered a daughter with his mistress, but then famously replied to those allegations with nothing more than 'So what?' and went on to continue his career with very limited impact. France isn't the US though, I guess.

Let's be serious here, whatever arguments McConnell had at the time he refused to even consider Merrick Garland's nomination (as opposed to voting him down) in 2016 were shown to be utterly meaningless when he chose to ram through Amy Coney Barrett's nomination so shortly before the 2020 presidential election. Even though I actually like Coney Barrett and think she's shown herself a valuable asset to the SC.

With Senate customs like the filibuster and the 'nuclear option', given the changed political landscape in which it looks like 60+ seat majorities for either party are a thing of the past and political polarization runs so high that bipartisanship is becoming quite rare, it seemed inevitable that one side or the other would get rid of such things simply because there's no way to get things done anymore otherwise.

The same goes for impeachment for that matter - whoever the target is and from whichever party, the procedure with its requirement to have 2/3rds of the Senate voting for conviction simply doesn't work anymore in this day and age, unless the target of the impeachment has irrevocably lost the support of a large part of his own party as well. Not that I'm suggesting that it should just require a simple majority - but I do suggest that since impeachment is in most cases no longer a viable solution, the arguments along the lines of 'presidents can't be prosecuted for any criminal actions taken in office, only impeachment should be used for those' fall flat, since impeachment isn't realistically going to happen to any president who isn't already extraordinarily unpopular, regardless of whether he did or didn't commit any crimes.