See the Daily Mail article posted here, though. Trump was outpolling Biden nationally in a two person race recently. Now with Kennedy in the race, they are saying it’s dead-even. So while the spin here is that Kennedy helps Trump, the spin there is that he helps Biden. Granted, elections are decided at the state level in the swing states, but the only poll that counts is the one a year from now.
Voters see RFK Jr. and wonder who was RFK Sr. They find out that RFK Sr. was the brother of former president JFK Jr and all 3 was/are democrats. RFK Jr. hurts Biden more than Trump if he manages to be on the ballot in critical states on November 2024.