Perhaps Joe Biden is determined, for the best reasons or the worst, to be the Democratic Party's candidate for President, despite misgivings engendered by his recent debate performance. If that is the case, Joe Biden will be the Democratic Party's candidate for President. He won the Democratic Party's primary election.

Perhaps Joe Biden is not so determined to be the Democratic Party's candidate for President. If that is the case, you may never, ever know it.

As old and stumbling as Joe Biden may have appeared on the debate stage, the Biden Administration has comported itself with tremendous intelligence. Should it entertain a change of leadership, let's imagine that it will do so with the same intelligence. What would that look like?

First, over the next few weeks, expect any possibility of a change of leadership to be mocked, rejected, completely ruled out, in every public communication. This weekend's mini rebellion among pundits and Democratic Party has-beens will be crushed. Joe Biden may be too old, he may not be the candidate we'd want to save democracy itself, but he will be the only candidate we have.

All of us who do not want a second Trump administration will fall back into line. He has, in fact, been the best domestic policy President since Lyndon Johnson. Compare him to the alternative, not the almighty, we will say. It is not the doddering old man we are electing, but the remarkable administration that has somehow conjured itself around him.

It won't be an easy sell to politically detached swing voters, who decide US Presidential elections. A personal or symbolic connection to an imagined heroic leader may be more accessible to those voters than arcana like this adminstration's remarkable FTC, NLRB, CFPB, or its SAVE plan. Nevertheless the excellence of the administration's accomplishments will have the benefit of being true, and it will be all we have.

Why, if Biden is considering withdrawing, will his administration completely rule out the possibility of withdrawing? Because if there is continued, credible, will-he-won't-he chatter, that will weaken him and render his continued candidacy less tenable. And in order to successfully withdraw, he must withdraw from a position of strength rather than weakness within the Democratic Party firmament. Any succession must be a negotiated succession, and Joe Biden is his own BATNA.

As the Biden Administration quietly discusses a potential replacement ticket, ambitious strivers will try to preen and threaten their way onto it. It must always be credible for the administration just to walk away and stick with Plan A. Disappointed shadow candidates may be tempted to appeal to the public, via their duly elected representatives on the opinion pages of The New York Times. The administration must make clear that its response to such perfidy would be to shut the whole thing down and double-down on Joe Biden's status as the default and inevitable Democratic nominee for President.

The stupidest idea widely mooted is for an "open convention". Obviously, pundits love the idea. We can have a dramatic, fast-paced horserace to supplant this current one, which smells like mothballs and stale poop. But just because a game show is good television does not mean it is a good way to choose a nominee.

An "open convention" would have no meaningful democratic legitimacy. No one actually voted for the delegates who will appear at the Democratic Party convention. Democrats voted for whoever was pledged to Joe Biden. Which particular humans show up on the convention floor is determined by processes that are not meaningfully democratic. Those processes may seem "random", but they are not, they have all kinds of systematic biases towards certain kinds of enthusiasts and operatives not remotely representative of Democratic Party rank-and-file. Choice by convention delegates is not some defensible sort of sortition by the back door.

The only person with any democratic mandate to choose a successor to Joe Biden as Democratic Party nominee is Joe Biden himself, who won a Democratic Party primary open to the public at-large.

Putting aside endlessly contestable arguments about legitimacy, the whole point of switching horses is risk management. The only reason Joe Biden would and should step down is if he is sure his replacement would have a much stronger shot of winning the general election. Throwing the dice on an unpredictable disorganized contest, one that might become bitterly divisive and even inspire rioting or violence at a Chicago Democratic Party convention, does not meet that bar.

By the time of the convention, the identity of the Democratic nominee will be a fait accompli. Not-really-elected delegates will not decide, and should not decide. There are two supedelegates. They will decide.

The first superdelegate, of course, is Joe Biden himself. The second superdelegate is Kamala Harris. No change of ticket can occur without Harris' enthusiastic endorsement.

One way to win her endorsement is to put Harris at the head of the ticket. That might be a reasonable option! But observers underestimate Harris by presuming that she herself — me! me! me! — is the only alternative candidate that she would endorse. Harris ran in a Presidential primary, and withdrew quickly when she realized the electoral stars would not align for her.

The Biden-Harris Administration will study the politics of potential tickets as best it can. There may be some degree of bias, some tendency to overestimate the strengths and underestimate the deficiencies of a Harris-led ticket. But some degree of bias will be a limited degree of bias. If the Biden-Harris Administration comes internally to a conclusion that a different candidate would have a much stronger shot, Harris is not such an egotist that she will risk throwing the country to Donald Trump in exchange for a lottery ticket to become President. Of course, Harris will negotiate a cabinet position for herself, or a quiet promise of favorable consideration should a vacancy arise on the Supreme Court. But she will not stand implacably in the way of whomever the administration determines to be the strongest contender.

The most likely outcome of all of this is just what it was before the miserable debate. Most likely, the general election will be a contest between Donald Trump and Joe Biden. Biden might be implacably opposed to stepping down. Or, he may be open to the idea, but this delicate, Democratic-Party-internal dance to annoint a credible successor might break down. Some narcissist the administration decides against could take his case to the opinion pages. If there's too much of that, the administration will fall back to the inevitable and deny it ever seriously considered making a change.

But if ambitious Democrats prove willing to abide a discreet selection process, it is quite possible that the only two people who can choose their successor will do so.

Paradoxically, the more inevitable a Biden-Harris ticket comes to seem over the next few weeks, the more possible the emergence of an alternative becomes. But in no case is it very likely.