The undecided is a lot closer to 10%, perhaps a bit above so far. What RCP averages and Emerson doesn't do is to provide third party voters.
Going inside and averaging everything out, Biden 49%, Trump 42%, other or third party voters 4%, undecided or not sure 5%. From January until today, Biden has been between 47-51%, Trump from 40-44%. Compare that to 2016 when Hillary was between 40-44%, Trump from 36-40%.
In 2016 the third party/undecided from January through July averaged between 18-22%, 2020 7-11%.
The bottom line is in 2020 Trump must convince some Biden supporters to jump his ship and board Trump's train. There isn't that huge pool of 20% or so undecided/third party voters to pull from. In 2016, Trump didn't need to convince one Hillary voter to come over to his side.
It's high past time that we start electing Americans to congress and the presidency who put America first instead of their political party. For way too long we have been electing Republicans and Democrats who happen to be Americans instead of Americans who happen to be Republicans and Democrats.