South by Southwest canceled a panel discussion that on Saturday was to examine the voting power of independent Americans after the moderator objected to the 11th-hour inclusion of unaligned presidential candidate Robert F. Kennedy Jr.

Paul Rieckhoff, an independent political analyst and commentator, had been slated to moderate the discussion during Austin’s signature annual festival where the worlds of entertainment, popular culture and politics intertwine because he was “not comfortable with promising Kennedy involvement in any part of the program.”

In a series of posts on X, formerly Twitter, Rieckhoff said an unnamed SXSW “organizer” had planned to add the son of late U.S. Sen. Robert F. Kennedy and the nephew of late president John F. Kennedy to the program. The younger Kennedy, an environmental lawyer and an anti-vaccine crusader, dropped out of the 2024 race for the Democratic presidential nomination to run as an independent.

“I will not elevate or support RFK Jr.,” Rieckhoff, founder of Iraq and Afghanistan Veterans of America, said in one post. “For many reasons — to include his promotion of 9/11 conspiracies. Especially as a 9/11 First Responder myself.”

The post was an apparent reference to Kennedy saying on a podcast last year that he had doubts about the official account of the Sept. 11, 2001, deadly terrorist attacks on New York City’s World Trade Center and the Pentagon, including whether al-Qaida bore responsibility.

In the podcast, Kennedy said he was not a 9/11 expert, or perhaps the best person to comment on the attacks. But, he added, “I don’t always accept official explanations.”

In an unsigned emailed statement, SXSW said the late decision to include Kennedy in the panel titled, “Independents: Wielding the Power to End Polarization,” was to have included 2020 Democratic presidential candidate Andrew Yang and was among many deviations from the original schedule.

More: A 2024 frenzy? How RFK Jr. could chip away at Donald Trump and Joe Biden’s strategies

“This session about the Independent’s role in the context of partisan polarization and the upcoming election went through several last-minute changes, including speakers dropping out,” the statement said. “Ultimately, due to timing, the session organizer felt it was best to cancel.”

Rieckhoff’s office did not respond to an email seeking a direct comment. But he said in his social media postings that he would not have objected to Kennedy joining the audience for the discussion, but only to his planned inclusion in the discussion.

“I stated I could only remain if he attended just like anyone else. No special treatment or coordination,” he said in his post on X. “She (the organizer) pressed it, and others decided to remove themselves. I tried to salvage the panel without RFK Jr, and she decided to remove me as moderator and cancel the whole thing.”

Meanwhile, the Democratic National Committee said in a media advisory that it had commissioned a video message-board truck Saturday to drive through Downtown Austin where SXSW events are taking place linking Kennedy to Trump supporters.

This article originally appeared on Austin American-Statesman: Plan to add RFK Jr. to SXSW panel sparks objection, cancelation