Harris is unpopular with the public
Paz, Vox senior politics reporter, 24
[Christian Paz, Vox senior politics reporter, 7-21-24, Vox, “Does Kamala Harris give Democrats a better chance to win?,” https://www.vox.com/2024-elections/361750/biden-drop-out-harris-endorse-polls-against-trump-democrats-dnc, accessed: 7-21-24, ES]
Critics of the KHive — as the online superfans of the vice president call themselves — and the VP argue that Harris is still really unpopular with the American public. They argue that the polls don’t actually show that much of an advantage for Harris in battleground states or with the popular vote; they point to her failed 2019 presidential campaign and her tepid vice presidential tenure as proof she’s not a particularly good candidate or politician and would likely run an uneven campaign.
They also argue that Biden’s flaws and foibles are already built into the electorate’s mind, while the chaos and uncertainty of swapping in Harris would expose the Democrats to even more risks (like how voters react to a woman of color as a nominee).