The photo has two individuals in it. The interviewer is on the left, Amna Nawaz, and RFK Jr is responding to a question by asking one of his own, “does everyone in your family agree with you?” Amna’s response is to reply that, “I think that they’d vote for me if I ran for president.”

RFK Jr family has come out against his presidential campaign. I believe they have aligned with the Biden campaign.

The burn here implies that: if you can’t even get your own family votes, how can you expect to get American voters?

Edit: clarification of people