They will, but even if Harris performs as bad or worse than Biden it won't matter. It won't matter because the media is unison will gaslight on steroids. A worse than Biden debate performance will be sold as a huge Kamala win.
The only reason people like 4th, roundy, the King, Finding etc. turned on Biden is because the media told them it was OK to do so. Remember before 6/27 Biden's dementia moments were all cheap fakes.
There is no such option now for the media and regime to pivot to in the wake of a Kamala debate disaster.
Well that's not completely true, they could always just "retire" her at the hands of a MAGA lunatic.