I think all of this hand wringing over polls is misplaced, for several reasons.
One, polls themselves are mere snapshots of the electorate, and have notable biases. Clearly, they aren’t reaching an entire cross section of the voters, and may be missing out on new voter enthusiasm, or shy supporters (perhaps Republican women will break for Harris). The only true poll that matters is the one that occurs on Election Day.
Secondly, these forecasts are based on a massaging of these flawed poll numbers, by prognosticators with a bias, unconscious or not, towards a more conservative outlook; better to err on the side of a close race. Although it’s covered by numbers and statistics, this polling stuff is really just guesswork.
At best, they reflect a trend, that the wave of enthusiasm for Harris has softened, as all of those new supporters have already been added into the equation. But her lack of gains in recent weeks isn’t necessarily weakness.
Thirdly, there are certain inflection points to come which I think will have significant influence on the outcome of the election. The debate is the first one: if Trump appears tired or angry and bitter, it’s going to turn people off. There’s also that movie I mentioned upthread, which might get some buzz as it depicts Trump as a loathsome asshole. His DC indictment is moving, with Judge Chutkin holding hearings. Even if people don’t agree with, or understand, the underlying charges, Trump is being tainted with scandal. NY’s senfencing might happen this month, too.
Obviously, Harris or Walz could hit a snag; Walz has MAGA family members, so that could get ugly.
But Harris is focused on policy. She’s talking to people about their problems and their future. Trump is just talking about Harris, or about himself.
None of this is to say that the election is over, or in the bag. But there is ample room for optimism at this point, even as we are in the thick of the fight.