The grandson of President John F. Kennedy railed against his cousin Robert F. Kennedy Jr. in an Instagram post on Friday, accusing him of trading “on Camelot, celebrity, conspiracy theories, and conflict for personal gain and fame.” In the post, 30-year-old attorney Jack Schlossberg further blasted Kennedy Jr.—who is running for president as a Democrat—for refusing to endorse Joe Biden. “I've listened to him. I know him. I have no idea why anyone thinks should be president,” Schlossberg said, referring to his cousin. “What I do know is his candidacy is an embarrassment.” Last week, RFK Jr. faced blowback from other members of his family over his claim that COVID-19 may have been “ethnically targeted,” giving certain demographics outsized immunity.