Democrats have a much deeper bench that you appear to be aware of
There are a number of very electable Dem Governors who haven't been introduced nationally yet. And in the era of Trump, there are few "fatal flaws."
Senility is one.
I doubt Newsome's ex wife has any dirt comparable to Trump banging a porn star.
I think Whittmer is the strongest candidate. She recently won reelection in MI by a landslide and took both houses of the legislature when she did it.
If it has to be Kamala, Whittmer should be her VP.