To the extent that this thread is about the phenomenon as reflected on the Dope, I think it’s worth mentioning that we have experience with (and possibly some hypersensitivity to) what has been described as “concern trolling.”
Such that there may be a tendency to attempt to prioritize “accounting for it.”
I don’t think that’s a comparable thing at all to a presidential general election. The most obvious difference is that the overall system allows for two or more national car-rental companies to operate simultaneously and each be successful (profitable). Presidential elections are winner-take-all.
There is a significant difference between predicting the candidate will lose, and saying the candidate is behind. The first is long-term pessimism, something that social scientists have associated with the candidate losing. The latter is consistent with the kind of optimism that wins elections. Consider:
’ For Presidential Candidates, Optimism Appears a Winner
To the bolded: Not in the media, there isn’t. Not when speaking to a broad audience that includes casual followers of politics and those that barely follow at all. That is, a broad audience containing a lot of people who will accept the predictions uncritically.
Your link is paywalled, but appears to talk about an unrelated issue: Optimisim/pessimism within a president’s camp (the candidate themselves, campaign staff, etc.) versus optimisim/pessimism among the general electorate about a candidate’s chances.
It’s an integral part of their strategy of pretending that they wuz robbed in order to recruit support for various schemes to suborn or outright steal elections.
As for this just being about candidate optimism, yes. I haven’t seen any research on how optimism among internet denizens, or the general public, affects results. So I looked at what I had in hopes that it might be a little relevant.