About 40-45% of the country will vote for the dem candidate, regardless of who they are.
About 40-45% of the country will vote for the republican candidate, regardless of who they are.
That leaves the 10-20% undecideds up for grabs.
This election is going to get down to who turns off that 10-20% the most. Trump is a good candidate against opposition that also has very high negatives (see Hillary and enfeebled Biden). In a "who has the lowest negatives" race, Trump starts at a significant disadvantage. He is going to have to hope that once Kamala actually starts talking in public and really campaigning, her stupidity will bother people more that Trump's boorishness.
If he can manage to be the Trump from the first half of his acceptance speech for the next 3 months, it would help him considerably.
“Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy. It's inherent virtue is the equal sharing of miseries." - Winston Churchill