Drama reportedly ensued after conference organizers unexpectedly added Manigault to a panel, much to the displeasure of the other panelists already there.
Moderator and broadcast journalist Ed Gordon stepped in at the last minute, but he sparred with Manigault-Newman, nearly as soon as she stepped on stage.
"I fight on the front lines every day", Manigault-Newman said, provoking laughter and groans from the audience.
The pair ended up in a volatile exchange because Gordon wanted to talk about Trump.
Footage of the event has surfaced on YouTube, including cellphone video (above) shot by a reporter for Heavy.com who attended the panel discussion.
Heading into the forum, several journalists who were scheduled to be on the panel backed out over the addition of Manigault-Newman, who became famous after appearing on The Apprentice. She also noted that in her role, she is often the "only African-American representative" in the White House and frequently tries to be an advocate on behalf of black people.
"You don't walk away from the table", Manigault responded when asked why she would take a job in an administration they viewed as being hostile to African Americans, NPR reported.
The black journalists turned their backs on Manigault even though she said she disagreed with Trump's joke about how he did not want police to be "too nice" by putting their hands on top of the heads of "thugs" while throwing them "into the back of a paddy wagon".
She said that part of the problem is an unwillingness of activists to come to the table.
"It was that she was added at the eleventh hour and it was unclear whether we would be able to discuss substantive issues regarding the administration and its policing policies".
However, some attendees turned their backs on her as she sat down for the panel moderated by BET journalist Ed Gordon that included Philando Castile's mother Valerie Castile and Alton Sterling's aunt Sandra Sterling.
At one point, she accused the moderator of making light of her family's tragedy, which he denied.
Before giving the microphone to Glover, Gordon called the panel a "quagmire" that had "reached the point of diminished returns".
"I'm not going to stand here and defend everything about Donald Trump", she said, to loud sighs in the audience.