I'll walk you through this:
Mary Trump is already yesterday's news. Nobody cares.
Exactly why you refresh people's memories and boost her book sales.
Woodward doesn't drive voting. Never has.
That's not how these things work. Woodward helps frame a narrative and change perceptions -- or in this case maybe firm up the perception. This trickles through to how the rest of the media portrays Trump and the questions he is faced with. Everybody knows Woodward is always well-sourced, so they trust his writings.
Any media shift and re-emphasis due to Woodward will indeed trickle through into votes.
Just for instance, how does Trump keep downplaying Russian election interference when Woodward cites Russian malware embedded in some Florida voting systems?
It will have an effect ...
But more importantly, the book puts the focus back on his disastrous response to the Virus as Trump has been trying to talk economy and lawnorder. Trump can't really afford a week or two wasted rehashing all that went wrong with the epidemic.
And that's one of the challenges Woodward's book poses.
You're welcome.