I suspect the Democrats are thinking more about the office than Biden's longevity. If he makes it through four years, well and good. If he passes while in office then it's a nifty funeral and President Harris or Booker or whoever.
Democrats are crunching the numbers.
They may come to the conclusion the only way to beat a white man is with another white man.
They want to take back the White House - By Any Means Necessary.
If that means nominating a white man, they'll give Biden serious consideration.
Their goal is to Take Back Power. Biden may be a 'necessary evil'.
Now there's a thought to galvanize our base.