It's not too late.
DJT won on the substance, but the weasel Biden beat him on the optics. Optics, sadly, are what wins elections these days. You and I, dear FRiends can see through the fluff, but low info voters will go on instinct, derived from demeanor from a debate.
I believe very strongly that DJT can win the next (and final) debate, but only (ONLY) if he does not allow himself to be goaded into a spat.
Timing.
Timing.
.
.
...Timing
The bad optics were amplified by the "moderator."
When it comes to organizing the presidential debates, Trump's GOP is still the same old GOP we grew to hate: the LOSER party!