I know this is splitting hairs, but technically the respondents were not being asked whether Biden and Trump should run again. The question is about who the parties should nominate, and it’s:
Among Dems:
Someone Else 51%
Biden 45%
Among Republicans:
Trump 50%
Someone Else 49%
Just wanted to mention that because, as I recall from past polling, the number of Republicans who say they want Trump to run again is at least a bit higher than those who say that he’s currently their 1st choice for the nomination.
The poll also notes some past results on this question….
Dems being asked about their choice for 1996 Dem. nominee in November 1994:
Clinton 55%
Someone Else 35%
Dems being asked about their choice for 2012 Dem. nominee in March 2010:
Obama 76%
Someone Else 20%
Republicans being asked about their choice for 2020 GOP nominee in March 2018:
Trump 75%
Someone Else 20%