The Cook Report adjusted it's rating of Florida from 'toss-up' to 'Lean Democrat'. In my original post, it was polling significantly more friendly toward Biden than the other 'toss up' states in large part because Biden appears to be doing much better with seniors than any recent Democratic candidates.
Real Clear Politics
has a tool that lets you create what you think is the most likely electoral map. On the 'base map', Biden starts with 222 electoral votes to Trump's 115. 201 Electoral votes are listed as toss-up including Nevada, Arizona, Texas, Iowa, Missouri, Wisconsin, Michigan, Ohio, Pennsylvania, New Hampshire, North Carolina, Georgia and, of course, Florida (as well as one district in Maine and one district in Nebraska).
If Biden winds Florida without a single 'toss-up state', he would have 251 electoral votes. Winning Pennsylvania (20 electoral votes) would give him the victory, or winning basically any two states besides Nevada/Iowa (6 electoral votes each). For example, winning Florida, Wisconsin and Michigan would put Biden at 277 electoral votes. Trump winning every other battleground state wouldn't make a difference.
Effectively, that puts Florida into 'must-win' territory. It has been reported that internal polls that Trump relies on 'in aggregate' show him with a smaller share of the electorate in states he won handily - ie, winning Texas by 5 points when in 2016 he won by 9. A shift of 4 points toward the Democratic opponent. A universal 4% shift compared to 2016 results would shift the following States from the Republican to the Democratic candidate:
Nebraska's 2nd District, Wisconsin, Michigan, Pennsylvania, Arizona, Florida, North Carolina.
The National Polls of voters at the end of 2016 showed Clinton with a 2-4% lead (and a negative trend, with late breaking news about the FBI reopening an investigation); she ended up wining the Popular vote by 2%. If the electorate were exactly like the 2016 electorate (ignoring any demographic changes, or 'enthusiasm changes'), Trump would need to cut the popular vote lead down below 4% - that would potentially allow him to lose only Nebraska's 2nd District, Wisconsin, Michigan and Pennsylvania, which would result in 269 Electoral votes for Biden; Trump would have to win NV, AZ, TX, IA, MO, FL, GA, NC, OH, NH, ME2.
With 98 days to go until the election, this is just a snapshot, but it may explain why the White House is now endorsing a mask policy, and why the White House asked the governor in Tennessee to close bars (he is not doing so).