I suspect polling done already in mid-2023...shows only Newsom, Michelle Obama and Gov Whitmer have good odds taking on Trump.
Biden has re-stacked the cards....being hostile about pushed out, and intends to set things to fail.
Biden had to endorse his VP. What he didn't have to do was pick a radical Black Female as his VP. So Biden's insistence on PC/DEI cornered him.
However, do not be surprised if what we see and read is all smoke and mirrors. Why did Manchin, a far more dangerous candidate, say he may run for the nomination and then drop out the next day? Who spoke to him? Manchin is a RAT through and through but has a carefully crafted image as a moderate. People would look at Trump and Biden and see Manchin as a reasonable, less partisan candidate. The rules may have been against him since he would have had to re-register as a Democrat. But the RATS are changing their rules almost daily.