This is a bad piece, mostly.
The way this is presented is that it is an understood fact that any and all of these individuals are un-electable. Maybe they are, maybe they aren't, but this isn't a "sky is blue" truism.
Trump being convicted and removed from office is "fair and square." It's as much a mechanism of the Constitution as voting is.
The U.S. is a representative democracy. This is way off base and misleading.
The whole thing reads like a frenzied plea from someone who actually does think they might convict him, and he's begging them not to. The whole crux is "Pence can't beat the Dem nominee" but... Trump may not be able to either (especially if the evidence gets worse than it is). There's no consideration of downballot races in the piece, where the real concern and impetus for ditching Trump would come from.
I don't love the piece either, but I'm sorry, he's right on his main thesis. Yes, impeachment and removal is legal and fair. Yes, we know how representative democracies work.
And no, Republicans don't give a fuck. It takes two seconds on any conservative leaning site to see the mental loops they'll twist themselves into to defend their god-king. They do not care about the rule or law, fairness, or accountability; if Trump is removed, even quite legally and justifiably, they'll go absolutely fucking bonkers. The Republican party will be done. Straight up.
Anyway, who cares, impeach him. It's gotta be done and will hurt regardless.