Allan Lichtman, a historian, has predicted the winner of every single presidential election from 1984 to 2020 correct (except for 2000).
https://en.wikipedia.org/wiki/The_Keys_to_the_White_House
"When five or fewer of the following statements are false, the incumbent party is predicted to win the election. When six or more are false, the incumbent party is predicted to lose."
(In short: When at least six keys are false, the incumbent party candidate loses the presidential election)
The incumbent party candidate is usually the President. If it's not, due to being term-limited by the 22nd Amendment, then the incumbent party candidate is the candidate whose party is the same as the President's party.
So far, Biden has 4 keys confirmed to be "True" keys (No primary contest, Incumbent seeking re-election, Major policy change, and Uncharismatic challenger), and 2 keys are "False" keys (Midterm gains and Charismatic incumbent)
Out of the 13 keys, if the "Leans False" keys become "False", and the "Leans true" keys become "True", Biden would still win because, as mentioned before, it takes at least six false keys for the incumbent party candidate to lose.
If the "Leans False" keys become "False", and the "Leans True" keys become "True", it would look like this:
1. Midterm gains: False
2. No primary contest: True
3. Incumbent seeking re-election: True
4. No third party: False
5. Strong short-term economy: True
6. Strong long-term economy: True
7. Major policy change: True
8. No social unrest: True
9. No scandal: True
10. No foreign or military failure: False
11. Major foreign or military success: False
12. Charismatic incumbent: False
13. Uncharismatic challenger: True
5/13 False keys. A lot can change, but Biden is favored to win in November. As Lichtman said: "Forget the polls".
Here is the picture of his predictions as of now in case any key changes to "True" or "False":
