PHILADELPHIA (AP) — President Joe Biden has accepted endorsements from at least 15 members of the Kennedy political family.

The Kennedy family backing came during a campaign stop Thursday in Philadelphia as the Democratic incumbent aims to undermine Republican Donald Trump and marginalize the candidacy of independent Robert F. Kennedy Jr.

The decision to highlight the Kennedy family endorsement with Election Day more than six months away is an indication of how seriously Biden’s team is taking the threat of a long-shot candidate using the Kennedy name to siphon support.

RFK Jr.’s sister Kerry delivered the endorsements by calling Biden her hero.

RFK Jr. writes on social media his campaign is about “healing America.”