Kennedy, an anti-vaccine proponent who launched a primary bid against Biden this spring, is doing unexpectedly well in some polls and receiving increasing media attention as a result. He has also been on a press tour this week that included a Twitter Spaces discussion with Elon Musk and digital town hall with journalist Michael Smerconish.

Democrats widely consider Kennedy to be a problematic fringe candidate who freely spreads conspiracy theories. But his relatively decent poll numbers, as well as his media-ready image as an heir to the famous political dynasty, have caused some to worry he could gain steam and potentially distract from the task of reelecting Biden in 2024.

"Democrats would be foolish to mock or belittle RFK Jr. Every time we make fun of those who hold fringe positions, we lose," said Michael Ceraso, a Democratic strategist and former campaign aide to Sen. Bernie Sanders (I-Vt.) and Transportation Secretary Pete Buttigieg. "The Democratic Party acting smug never works."