Who is Robert F. Kennedy Jr.?

Many Democrats (and even some Kennedys) wish Robert F. Kennedy Jr. would simply slink away and disappear, like an embarrassing party guest.

But instead, RFK Jr., who launched his Democratic presidential primary campaign in April, has gained traction, especially among a subset of contrarian figures such as Elon Musk, who have cast him as a free speech hero.

Recent polls have shown Kennedy with anywhere from 12% to 16% support in surveys of likely Democratic primary voters, including a Yahoo News/YouGov poll from late May. But another poll from CNN the same month showed Kennedy with 20% support.

That doesn’t necessarily make him a serious contender for the Democratic nomination, but his famous last name has made him relevant so far. Kennedy is the son of slain former Attorney General and U.S. Senator Bobby Kennedy, who was assassinated in 1968 while running for president himself. He talks about himself as continuing the legacy of his father and his uncle, former President John F. Kennedy, who was assassinated in 1963.

Kennedy is also an avatar for a belief system that has become more popular in recent years: that the world is controlled by shadowy unseen forces who manipulate the public for money and power.

And Kennedy could potentially hamper Biden enough to help Republicans in the 2024 election.

Specifically, there is concern that in New Hampshire — which votes early in the process — Kennedy could perform well enough to embarrass Biden in next year’s primaries, which could ultimately help a Republican candidate for president win the state in the fall.

New Hampshire Democrats are fighting with the national Democratic Party, which has stripped the state of its coveted spot as the first primary contest in the nominating process. If New Hampshire defies the Democratic Party’s decision and goes first anyway, as it seems intent on doing, it would render the contest noncompliant, the result would not count, and Biden’s name would not be on the ballot there.

That would give Kennedy an opening to gain vote share there and claim a moral victory. And it would also probably divert voters, who could vote in either primary, toward the Republican primary, possibly influencing them to vote Republican again in the fall election.

“Kennedy won’t win, but he can hurt Biden, and that’s the point,” said Mary Anne Marsh, a Massachusetts Democrat who worked for Robert Kennedy Jr.’s uncle, Sen. Edward M. Kennedy, D-Mass.

Kennedy’s stated rationale for his campaign is that the Democratic Party has forsaken the working class and poor, and that he is summoning it to return to their side.

But Kennedy is best known as a vaccine critic. He has devoted himself for years to questioning the safety and efficacy of numerous vaccines.

Then COVID-19 made him into a folk hero to those who believe that social media companies were wrong to remove, or limit the spread, on their platforms of claims opposing the evolving medical consensus during the pandemic.

A 2021 Associated Press investigation into Kennedy’s claims about the COVID vaccine found that he had contributed to “a disinformation echo chamber that reinforces false narratives that downplay the dangers of COVID-19 while exaggerating the risks of the vaccine.”

Kennedy’s campaign centers on his claim that the government and big business are working together to benefit the rich and oppress working people.

“My mission,” Kennedy said during a nearly two-hour speech announcing his candidacy, “will be to end the corrupt merger of state and corporate power.”