Let's see I have a choice of a Marsist Poll which has had high accuracy ratings for the last two election cycles or your conclusion that "he would undoubtedly do more damage to Biden."2016 taught me to never trust polls. If you need evidence just let me know. I wouldn’t consider myself a Trumpster, but I’m definitely a conservative. I don’t fear Kennedy taking Republican votes. He would undoubtedly do more damage to Biden as you look at his approval ratings even among Democrats.

I think I would go with Marsist. There are a lot of Republicans who can no longer abide Donald Trump. That doesn't mean he can't win, but it does likely mean he can't afford any erosion of the support he had 2020.
And before anyone gets too exercised over FiveThirtyEight or Bloomberg, that assessment was done after those elections. I posted it here because it represents a factual input that is likely worth considering. I know many prefer this discussion to be an echo chamber, so feel free to reject it.
The Marist Poll is conducted by the Marist College Institute for Public Opinion in Poughkeepsie, New Yorker. The institute was founded in 1978 as a college-based research center conducting local, state, and national polls.[1]
Bloomberg Politics and FiveThirtyEight rated The Marist Poll as a top pollster for its accuracy in 2016 and 2020, respectively