Let’s be frank: the polling is awful
By 
The conclusion you want to draw from this is up to you, and you can try to UNSKEW THE POLLS if you want, but I don’t think the data is ambiguous at this point:
Donald J. Trump’s lead in the 2024 presidential race has widened after President Biden’s fumbling debate performance last week, as concerns that Mr. Biden is too old to govern effectively rose to new heights among Democrats and independent voters, a new poll from The New York Times and Siena College showed.
Mr. Trump now leads Mr. Biden 49 percent to 43 percent among likely voters nationally, a three-point swing toward the Republican from just a week earlier, before the debate. It is the largest lead Mr. Trump has recorded in a Times/Siena poll since 2015. Mr. Trump leads by even more among registered voters, 49 percent to 41 percent.
Doubts about Mr. Biden’s age and acuity are widespread and growing. A majority of every demographic, geographic and ideological group in the poll — including Black voters and those who said they will still be voting for him — believe Mr. Biden, 81, is too old to be effective.
And remember, given the electoral college bias (which has probably been mitigated by Dobbs but hasn’t gone away) if Biden is tied he’s losing.
I think that Biden deserved the benefit of the doubt until the first debate that he insisted be early. It would at this point require the deepest denial not to acknowledge that he’s forfeited it. And given that this is going to be the Comey letter every day as long as he’s in the race, how much of this impact on public opinion is from people who watched the debate themselves and how much of it is negative media coverage is a moot point. The next person to come up with a remotely plausible explanation for how Biden recovers from this will be the first. And if it’s unfair to the extent that Trump is still far less fit to be president, well ugatz fair — alas the Electoral College doesn’t weigh it.