Here is the internal polling that was released, this was before Biden resigned
Through 7/21, Biden trailed Trump 46-44 nationally; Harris was ahead 48-46. Trump is stuck at a ceiling of 46. Harris gains from 3rd party/undecided voters.
Young voters (18-34) go from Biden 44-36 (+8) to Harris 57-37 (+20)
Independents go from Trump 48-32 (+16) to Trump 49-41 (+8)
Harris picks up 7pp among Black voters and 8pp among Hispanic voters, almost all from 3rd party/undecideds
Here is the internal polling that was released, this was before Biden resigned
Source: https://x.com/DrewLinzer/status/1815491120677458288