There was a lot of "it's over" when the failed attempt on Trump's life occured. There is currently a lot of mockery of Kamala Harris. I said way back in July of 2020 that a vote for Biden was actually a vote for whoever his VP pick was (this was before he picked Kamala). I didn't expect that they'd let him do a [nearly] full term but that's what happens when you make predictions. That said the above image is important.
Remember that Harris finished dead last in the 2020 primaries. She was offed by Tulsi. Harris had ZERO delegates. She was put in place as a "black" token to get Biden over the line with an extra "oomph" of black voters doing the "support the black woman" thing.
How does someone who had such little support get a 48% support rating in a poll (which I do not believe is an abberation)? Divided electorate. Dems are voting blue regardless. They will be joined by Never Trump Republicans.
In a long past America, it wouldn't even be this close in a poll. In current America, the rest of the season is going to be the [relatively young] female POC candidate against the old and young racist and sexist white men. On the side, straight black men who don't seek approval from black women will be castigated at every turn as "white adjacent" a la -Joy Reid.
Harris is very vulnerable on the issues but I'm not sure how much issues are actually going to be in play.
Either way, the above shows that the Trump team better be on the ball (and that alleged dismissal of RFK Jr.'s overture may be unwise).