

I thought the subject was about how NOT to have somebody like Trump in power, which naturally means examining EVERYTHING that led to somebody like Trump ending in power, which certainly includes looking at how and why did the other party in the power duopoly system in the US field such a horrible candidate that she lost against somebody as bad as Trump.
Of course if your “subject” is not “how best to beat/avoid a Trump president” and instead is “the electorate should be subservient to the choices of ‘my Party’s leadership’”, I can see how it would seem to you that I changed subject by not going along with the whole “the choices of the DNC are above challenge by the riff-raff” view.
Party loyals never challenge the choices of those they see as their betters - the Party leadership - and instead blame the masses for not going along with them: it’s never “how can we better make sure people want to vote for us” and always “people are horrible for not voting for us”.

I’m sorry but that’s only “rational” if your analysis is very superficial.
Tactical voting is exactly what has been happening in the US for DECADES and the outcome was ever more rightwing policies, social mobility crashing from almost 90% in the 70s to just over 10% now, increased poverty and so on, and even putting aside all social and economic issues and focusing only on political strategy, with this system the Democrat Party has not once but TWICE fielded a candidate so bad that they lost to somebody like Trump.
Logically doing more of the same would yield more of the same outcome - ever more rightwing populists getting elected - and the next time a far-right POTUS is elected (a guaranteed event if desperate people keep getting created in the US by falling median real incomes and opportunities alongside a captured Press specialized in blaming foreigners for it, because both parties have neoliberal policies) that next Fascist POTUS might actually be intelligent and hence even more dangerous than Trump.
Even in a fucked-up, undemocratic, power-duopoly system like the one in America, each vote isn’t simply an A/B choice that’s closed once done - the way things work in the US a vote is a cyclic choice where parties put forward their choices for candidates and the voters say “yes” or “no”, and then some years later the same happens again, so the response of voters to the candidates fielded in one cycle informs who the parties put forward in the subsequent cycle.
In other words, if people keep rejecting a certain style of candidate fielded by a party, that party is pushed to field a different style of candidate. This how the Republicans changed over the years fielding ever more far-right and populist candidates - voters responded badly to “serious conservatives” so the party fielded more and more “anti-immigrant loudmouths”. It’s funny that Republicans have been more responsive to their electorate than Democrats.
So each vote isn’t just a choice of POTUS, it’s also a message to the parties about the suitability of the candidate they have fielded and, last I checked, in Democracy it’s the obligation of parties to responde to voters rather than the other way around.
Under this broader analysis, the Kamala vs Trump result yields two possible views:
As I see it, if one is trully not a party loyalist and genuinelly wants avoid another Trump in the future, the most logical choice is to go with #2 for three reasons:
If one’s objective trully is to avoid having another Trump in power in the US, then logically the most effective way to do so is to push the DNC leadership to change (or replace them) since those people are VASTLY more powerful than votes and are fewer in number so change there is not only way more effective but also more likely.
Sadly, there’s a lot of people driven by party loyalism parroting “blame voters” self-serving propaganda from the DNC in order to avoid that those party leaders suffer repeatedly choosing candidates that don’t appeal to voters.