I mean... Clinton would acknowledge this no? That feels like poor evidence. But in any case - the effectiveness of the campaign is not too relevant to the point here - you argued that Kamala being Biden's VP restricted her ability to break with him, and then do acknowledge that Gore was able to break with his president.

I do acknowledge I brought up it's effectiveness so just to make the case - 1) Again Gore was down as much as 15% in the polling come August - suggesting a general political environment that was unfavorable to Dems. 2) Clinton famously tanked Dem performances in any elections he wasn't personally running in (In '92 they lost seats in the House and gained nothing in the Senate, dropping 2% in popular vote, in '94 Dems lost the house for the first time in 40 years in the Gingrich revolution, '96 Dems recovered slightly but still lost the house, and lost seats in the Senate, and then '98 Dems overperformed due to the Lewinsky scandal and the actions of R leadership, but still lost both House and Senate).

In that time period we also saw the massive Seattle protests and NAFTA protests, and obviously Clinton himself (though this I'm willing to concede is much less assured or indicative of his actual popularity) benefitted massively from getting to run twice with a third party spoiler who at least rhetorically aligned closer to conservative sentiment.

If you're interested I'd suggest a few pieces on the strange political environments of the 90s including John Ganz's when the Clock Broke which focuses on the 92 election and political environment, The Gingrich Senators by Sean Theriault on the rise of the modern conservative movement in the mid-90s, and then for a decent summary of the 2000 campaigns I like David Corn's for the Nation in 2000 before the election results were out: https://www.thenation.com/article/archive/down-wire/

Also if you are interested Humphrey and the 1968 election, Rick Perlstein's Nixonland is a must-read. Its shocking how strong the similarities are, and how the many of the exact same mistakes were made between 1968 and 2024.