Harris NOT tied to Biden polling.
Skelley and Morris 7-22 [Geoffrey Skelley and G. Elliot Morris, ABC News correspondents covering the 2024 election. “What do the polls say about a Harris vs. Trump matchup?” July 22, 2024. https://abcnews.go.com/538/polls-harris-trump-matchup/story?id=112162146]
Ultimately, Harris's seeming upward trend in the polls and the fact that she's polled better than Biden in many recent surveys will give Democrats reason to hope that she has a higher ceiling of support than the president, whose polling numbers had remained pretty stagnant throughout the campaign. This seems especially true because fewer Americans have expressed an opinion about Harris than Biden in approval polling. In theory then, the public has less concrete views about the vice president, which could allow her to win over some voters who didn't want to consider Biden.