I am very sceptical with regards to what one can deduce from early voting, but what is the overall picture here? From what I can gather, the numbers don't look as encouraging for Biden as one would like, especially given that republicans are expected to outnumber democrats significantly on election day turnout. What gives?
it’s possible that republicans are cannibalizing their own numbers by voting early, which would reduce their upside on election day (it might not be as lopsided as initially expected). also, a high turnout election would suggest high numbers both for democrats and republicans; the main reason behind biden’s lead is his winning over a significant number of republican voters while keeping most democratic voters—this crossover voting wouldn’t be reflected in the registration/ID numbers