Overall, it would hurt Trump if RFK Jr dropped out. There are far too many people, especially Dems, who view it as a “civic duty” to vote armed with as little knowledge as possible. Among those, are never Trump anti-establishment types who desperately want to pull the lever for anybody other than Trump or the DNC mystery meat of the day. That said, I wouldn’t mind an RFK Jr in the admin in some limited capacity. But please, run Robert, run!
I think the entire Kennedy klan should go the way of the Bushes. Don’t bring them to the forefront.