What difference will Harris make to the outcome

so now Trump has bit the bullet that winged him and relented to agree to debate Harris.

good job Mr Former POTUS. some respect.... lets see what follows.

Harris, its been said numerous sites, is an accomplished prosecutor. Trump might yet have something to hide. as I understand politics the usual suspects are microscopically examined for weaknesses so I'm sure Harris has a bit of extra deep digging to catch up with Trump's dossier on her.

on the other hand Trump has been attacking Harris diligently for around 5 years. he's possibly said all that can ever be said to damage her already. he'll just need to reinforce all those salient allegations against Harris.... I'm sure there are many.

will Harris make Trump the defendant? will Trump battle her for the prosecutor role?

which will win?

and what difference would a Harris candidacy make to Trump's polling?