An interesting, but not surprising, article on why the Kennedy family isn't backing RFK, Jr's presidential campaign.

https://edition.cnn.com/2023/04/16/politics/robert-f-kennedy-family-biden-2024/index.html

Or at least it may be interesting if, you grew up in Massachusetts and/or are old enough to remember the Kennedy family's political heyday.

As to why they aren't backing him:

1. He's a conspiracy-mongering nutter.
2. They (correctly) think he has no chance of winning.
3. They worry he'll tarnish the family brand
4. They like Biden.

Ultimately, for most people under around 45 or so, the Kennedy's just don't have the same cache they did for earlier generations. Even a less nutty candidate that RFK Jr would have trouble riding the family mystique to the White House these days. If you want a political career, it's still much better to be a Kennedy than an ordinary (non-Kennedy!) Joe. But the difference is much smaller than it used to be.