Days after Donald Trump trashed Robert F. Kennedy Jr. on social media, a poll released by Florida Atlantic University and Mainstreet Research suggests the 2024 presumptive Republican nominee has some reason to worry about the third party candidate. The national poll showed President Joe Biden leading Trump by a single-point in a statistical dead heat, 47% to 46%, among likely voters. But when RFK Jr. was added as an option, Biden's lead grew to 5 points, 44% to 39%. The survey of 1,046 adults has a 3-point margin of error.