Can resolve, I think?

Serious challengers often don't win any states. Ex. Gary Hart.

@MaybeNotDepends (or at least candidates). Gary Hart was leading the polls in 1988.
https://en.wikipedia.org/wiki/1988_Democratic_Party_presidential_primaries

How does this resolve if Biden withdraws, either before or after securing the nomination?

How does this resolve if Biden doesn't run?

@PeterWildeford my assumption is YES

@Nico ?

@BrendanFinan YES seems extremely non-obvious to me. If he’s not even in the primary, how can he “face a primary challenge?”

@MattCWilson +1, basically all of my NO shares are intended to say that no primary will happen

Why isn't the Democratic party more concerned about Biden's electability in the general? This, by far, is the biggest argument in a primacy. DeSantis would kill Biden in general.

@AlexKChen Incumbent presidents have a massive advantage. It's nearly impossible for any challenger, no matter how popular, to match it, even if the incumbent is relatively unpopular. He's at 43.3/51.3, -8%; that's not nearly unpopular enough for a reasonable challenger to think they can do better. And a primary challenge that fails damages the incumbent and their party, usually quite badly. Primarying a sitting president doesn't happen because it's a nearly guaranteed path to failure both for the challenger and for their party. And it will be blamed on the challenger - their name will be mud in the party back rooms for a decade or more. (In the words of The Wire: "If you come at the king, you best not miss.")

Also, The LBJ Line is -16% net favorability, the last Gallup approval poll before he announced he wouldn't run. The Carter line, bad enough that Ted Kennedy announced his primary challenge, was worse: -23%. If we see Biden drop down below LBJ, we might see a serious bid to contest the primary... but more likely we'd just see a withdrawal. Biden's a lot more like Johnson than Carter, in more ways than one.

@JiSK Biden's age is a huge turnoff (and a completely new variable), especially for GenZ voters (whose turnout problems are way more of an issue).

@AlexKChen Also even most DEMOCRATS would prefer someone other than Biden run, and I'm sure much of this is because they also perceive that Biden is a huge drag in the general election (much of it because of his age).

@AlexKChen Not a new variable at all. Didn't affect FDR, didn't affect Reagan, didn't affect Wilson. Biden's approval among Democrats is 76%. I can't find historical breakdowns by party, but he is in other respects in line with the usual trend for presidents in their first term.

Most democrats may prefer he step aside in favor of an open primary... but if he doesn't, they'll get in line and vote for him over the challenger, like always. And the challengers know that.

Biden can close the primary if he runs for reelection. He is the head of the party, an open primary requires resources and planning for things like caucuses and debates. If he runs there is zero chance the DNC spends money to do that and will will close the primary.

@BTE So you’re saying if AOC (for example) wanted to contest the primary, there is no path for her to do so if Biden didn’t want her to? So no incumbent president could be primaried? This is not what I’ve heard before.

@Nico That is correct. Why would the party let that happen? I suppose AOC could say that she will raise money to pay for debates, etc but again, why?! Ted Kennedy did this to Jimmy Carter and in the process killed his secretary and the Democratic Party for the next decade.

@BTE “Ted Kennedy did this to Jimmy Carter”. Right, so it’s possible even if it is unlikely. That was my understanding.

I’m interested though to hear more about the rules of challenging. Under what circumstances can the DNC close the primary? If a candidate with a reasonable level of support in the party declares their intention to run, can the DNC just ignore them? Would the rank and file/the challenger have any way of challenging such a decision?

@Nico Those are great questions. I am pretty sure Mark Sanford challenged Donald Trump in the GOP primary in 2016 now that I am thinking about it. Both parties make their own rules and can change them anytime for any reason.

If Biden does not run for reelection, is this also a YES?

@MattCWilson Thanks Matt, good question! I think if he announces he won’t run subsequent to a major challenger declaring, then YES. In other words if it looks like he is withdrawing because it looks like he’ll lose. Otherwise N/A makes more sense.

@Nico Not N/A, 'NO'. If he is not in the primary, he cannot face a primary challenge.

What counts as a primary challenge? Would the people who challenged Obama in 2012 or Trump in 2020 count, or does it need to be a serious challenge?

@lisamarsh Thanks Lisa. I’m thinking a serious challenger and I’ve updated the description to reflect that. If you’ve got any ideas for what else could qualify as a serious challenger, please do say!

@Nico Id probably say someone who polls greater than a certain percentage of the primary vote. Honestly don’t know what that number would be but 2-5% seems reasonable