Is the race tightening? Here is the current state of play according to RCP, if the polls are to be believed and there are no ties: Biden 357-Trump 181.

However, in aggregate most state polls show that the race is tightening. The NYT notes that this is because of the influence of two polling companies which have consistently been biased in favor of Trump. https://www.nytimes.com/live/2020/presidential-polls-trump-biden#one-of-trumps-better-days-but-look-a-little-closer HT @SykesCharlie

However, after 2016, one might conclude that most polls are still undercounting Trump support overall. So this is what the amp would look like if they were undercounting Trump support by 3%: Biden 290-Trump 248.

Let's assume, for the sake of argument, that the polls were across the board five percent wrong. At the moment, this is the only way Trump could win, with PA making the difference, with the final tally being Trump 279-Biden 259.

However, note that Trump is already getting about +5 in PA from several polling firms, meaning that the polls would have to be in aggregate about ten points off in Pennsylvania for this to be true.

So, while the race does appear to be tightening a little when we look at state-by-state results, some of this could be polling biased in Trump's favor. Even if we assume the opposite--that polls are biased in Biden's favor--he is still in pretty good shape.