Take away the white vote? That’s a pointless statement. Whites are still the majority in this country, so of course how whites vote will have a large effect on elections.
While racism certainly may play a part in why dome don’t think Harris has a chance, it’s not the only possible reason.
And while Harris, assuming she were to get the Democratic nomination (not at all a certain thing), would definitely have a chance to win the presidency, that doesn’t mean it would necessarily be a good chance. It’s hard to predict with much accuracy considering how far away the next election is. If the Republican candidate isn’t horrible, and if the Trump administration doesn’t make things so bad that any Republican candidate is tainted by it, I don’t look at Harris as a great candidate for Democrats. She wasn’t particularly popular in trying to get the 2020 nomination, she wasn’t all that popular in 2024 (although to be fair, the party stuck her in a bad situation with the way they handled Biden’s candidacy), so I don’t know why I’d expect her to be popular in 2028.
Again, it’s possible she could win simply by being the Dem candidate if the Trump administration fosters enough ill will in the electorate, like in 2020. I just don’t think Harris’s political history supports the idea that she is an especially popular candidate.