Given how stupid American voters are, I'm going to go ahead with "hope for the best but expect the worst" here. I hope to be pleasantly surprised, but I'm sure not going to expect it.
Biden doesn't have to give anyone anything. He will be the nominee, provided he has a pulse, and he can easily raise enough money to win his election and help downticket democrats. Everything else is a distraction.
The real trick is, if we see a democratic majority in the house and senate (unlikely, but possible), how will the Democrats avoid the progressive agenda then? Who can they blame for the lack of progress? Probably the courts, and obstructionist Republicans, both problems they could avoid if they actually wanted to pass a progressive agenda.
The current Republican majority in the house is completely due to gerrymandering. I mean that if we had eliminated all gerrymandered districts (going both ways) in America in 2022, the Democrats would hold the House today.
There are lawsuits out in a number of states. The Democrats will almost certainly gain several seats in New York state alone (possibly up to 6 or 7). And there are lawsuits in a ton of southern states from Florida to Texas, where after a recent Supreme Court ruling, it's likely that several of these states will end up with 1-2 additional Democratic seats each (with an equal number of lost Republican seats).
It's possible that political winds will swing further against the Democrats by 2024 elections, but it looks right now like those winds aren't the only consideration.
I think the reason he might be more of a threat to Trump than to Biden is that instead of splitting the Democrat vote, he's more likely to split the insane/idiot vote.
We need to start nipping this in the bud. RFK Jr. isn't your grandfather's Kennedy. He's more akin to a Republican in many ways.
Anti-Vax. The guy believes that vaccines cause autism.
He believes COVID 19 was engineered. He thinks it attacks Whites and Blacks, while somehow immunising Asians and Jews.
He believes Fauci and Bill Gates used COVID 19 to push for vaccines, to give us all autism?
He thinks the CIA killed JFK.
He thinks prescription drugs lead to mass shootings.
There are a few things I can agree with. Yes, I do think the pharmaceutical companies have hooks in the government. I think they are joined by other corporations as well, as money = power and we follow the "He who has the gold makes the rules" version of the Golden Rule here rather than "Do unto others as you'd have them do unto you" version. And I'm sure shenanigans were done in 2004 to get Bush over the hump, though Kerry did our side no favours. But the bottom line is that this guy is going to draw away even more people from our coalition. We need to remind each other than 74 million Deplorables came out of the woodwork in 2020 to cast their vote for Trump. We'll need every last person who does not want a Trump-Repeat to vote Biden and ignore shiny objects like RFK Jr.