IMO, it is going to come down to how much the Republicans get people to vote early. The last election went bad for them because people didn’t trust voting by mail and there’s always a contingent of people who intend to vote on election day but don’t make it for one reason or another. Political junkies should also watch the weather forecast in close states. Bad weather probably favors Democrats in this election. This is a change from the 80’s and 90’s when Democrats were less likely to show-up during bad weather.
If you look at early votes, Republicans are doing better in every close state other than Pennsylvania. So assuming there’s a correlation with party affiliation, the polls are probably correct. If Harris is going to pull this off, she needs to address the ground game in these pivotal states.