They say Harris has moved more towards the center or even consrvatism, for example she was principally against the death penalty and supposedly she's changed her mind. Whether I was for or against capital punishment I would see her as having weak core values, like you just changed your morals, and for what? Just to win the election?
She's weak right now in certain core demographics that the Democrats usually don't have to worry about. A lot of the Latins are far more conservative than the Democrats give them credit for. Also there's been a Black male shift which is noticeable. They don't like influx of illegal immigrants, and they remember that Harris was tough on crime in California years ago. They're also not digging the "code switching" that's been going on for years, where they Black or White it up depending on the audience.
It's not huge, but it's noticeable.
There's also a the hurricane problem, lots of rightfully angry people are pissed because of the government response.
They're in a rock and a hard place scenario right now.