Chris Wallace says Biden blew 'a big hole' in Trump's 'mentally shot' claim with DNC acceptance speech
I think that is more of Chris Wallace's liberal wishful thinking.
One speech relatively well read from a teleprompter still has plenty of time to fade into insignificance in a sea of gaffes, media-dodging, bad policies, general bad campaigning, cringeworthy virtue signaling, Democrat infighting, and who knows what else!