My opinion is somewhat opposite to that.
I think the GOP were positioned to make this an absolute massacre. They even slow walked their attacks on Biden as it was becoming apparent that calls to have him step down were growing louder. And they didn’t want him to do that.
I think they were in a position to think that it was too late in the game for the Dems to pivot this fast.
They have shifted gears. It’s DEI attacks on her, birther garbage and such. Because they’ve used that sort of stuff before and didn’t have anything on hand. They will I’m sure craft a new strategy but right now it’s a lot of lashing out.
No one is talking about the assassination and no one is talking about their recent conference where they came out with wind in the sails and now having it all stolen by Harris and her record breaking fund raising.
But things will balance out and I suspect this will be a very close race.