This is the 17th nationwide poll since October that has pitted both Biden and Harris against Trump, per 538.
It's also the 17th poll in which Harris doesn't outperform Biden. (It's the first in which she doesn't underperform him.)
Newsom has been polled seven times during the same period. He's matched Biden twice and underperformed five times.
If you take the average of the results, though, Newsom looks worse than Harris - she underperforms Biden by a little under 3%, Newsom by a little over 4%.
State-level polling looks a little better for Harris. Out of 22 state-level polls, she's outperformed Biden in four (GA, MI, NV, PA, all in November). On average, she runs around 2.5% behind Biden.
Newsom, on the other hand...
It's true that he's outperformed Biden in two out of nine state-level polls to date (marginally better than Harris), but one of those two states is California, and on average he runs behind Biden by.
Uh.
A full 7%.
The only other Democratic politician to get more than two national or two state-level polls is Whitmer.
Out of four nationwide polls, she's outperformed Biden in two, but the average still puts her nearly 3% behind Biden, same as Harris.
Whitmer also outperforms Biden in two of the four state polls she appears in, and matches him in a third. But all three of those polls are in Michigan, and doing well in your home state is table stakes, not proof of nationwide appeal.
In the one non-Michigan poll (OH), she's down 5% vs Biden.
Nobody else has appeared in more than one or two national polls or one state poll. I don't think that's a large enough sample size to draw any sort of conclusions.
I'm excluding Michelle Obama (three polls) because she hates politics and will absolutely not run, stop writing fanfiction about her.
