In a way, we’ve been here before. A presidential candidate seemingly unfit for office but nonetheless in position to be his party’s standard-bearer. A media drumbeat demanding that somebody, somehow, step in and push him out. A raft of party leaders and important officeholders hanging around uncertainly with their fingers in the wind.

As with Joe Biden in 2024, so it was with Donald Trump at various times in 2016 — both during the primary season and then especially in the fall when the “Access Hollywood” tape dropped and it seemed the G.O.P. might abandon him.

For Biden and his inner circle, an arguable lesson of that experience is that they aren’t actually finished, they don’t have to listen to the drumbeat and they can just refuse to leave and spite all the naysayers by winning in the end.

After all, it didn’t matter that not only the mainstream press but much of right-wing media deemed Trump unfit for high office — that Fox News anchors tried to sandbag him in the early Republican debates, that National Review commissioned a special issue to condemn him, that longstanding pillars of conservative punditry all opposed him. It didn’t matter that his rivals vowed “never” to support him, that the former Republican nominee for president condemned him, that leading Republicans retracted their endorsements just weeks before the election. Trump proved that nothing they did mattered so long as he refused to yield.

But I don’t think history will repeat itself. I think Biden will bow out, his current protestations notwithstanding, because of three differences between the current circumstance and Trump’s position eight years ago.

First, while both political parties are hollowed out compared with their condition 50 years ago, the Democrats still appear more capable of functioning and deciding as a party than the Republicans. Biden’s own presidency is proof of that capacity: He became the nominee in 2020 in part because of a seemingly coordinated effort to clear the field for him against Bernie Sanders, exactly the thing the G.O.P. was incapable of managing four years earlier with Trump.

This greater party capacity is, in part, a reflection of the fact that Democrats generally seem to like and trust their leaders more than Republicans trust theirs — and especially more than Republicans trusted their leaders during Trump’s rise to power. Figures like Barack Obama and Nancy Pelosi are seen as successful and admirable and ideologically reliable by their co-partisans, whereas in 2016 Mitt Romney and John McCain were perceived as political losers, the party’s congressional leaders as unreliable at best and the most recent G.O.P. administration as a failure. That means if leading Democrats reach the point where they tell Biden, “It’s over,” they’ll have more credibility and leverage within their own coalition than any Republican leader had in 2016.

Second, having the media and the intelligentsia turn fully against you is more devastating for a Democratic president, because the Democrats generally see themselves as the party that trusts the mainstream press and academic expertise and respectable opinion, whereas Republicans generally assume that those forces are biased or blinkered or somehow out to get them.

To be sure, there are plenty of Democrats who regard the wave of negative coverage for Biden since the debate as a put-up job or a media conspiracy; social media is full of those voices at the moment. But in its natural posture the Democratic Party really cares about its reputation among figures of cultural authority in a way that the Republican Party in its natural posture does not. So Biden’s incapacity, and the wave of elite anger at its concealment, has already created a greater sense of tension for Democratic politicians and staff members and apparatchiks than could ever exist on the Republican side.

Finally, even after Trump’s most disgraceful moments in 2016, Republicans found ways to reconcile themselves to his candidacy, to take the path of least resistance, by telling themselves that things might get better — that he could hire better advisers, lay off social media, learn to discipline himself, grow into the role of presidential candidate or ultimately president.

This was mostly self-deception, but it was a story that people could cling to or talk themselves into as a means to avoiding difficult choices. (And there were, in the end, more and less stable periods of Trump’s presidency, depending on which subordinates he hired.)

With Biden’s condition, though, even the most ardent partisans have to know in their hearts that things will not get any better, that they can only deteriorate from here. Hoping for a moral breakthrough or a sudden discovery of personal discipline from a public figure is generally naïve. But hoping for a reversal of the aging process is a different level of delusion, a higher bar to clear.

Some Democratic partisans are showing they can clear it. But not enough, I think, for Joe Biden to simply dig his heels in and survive.