Video captured by The Lantern showed the man being hit from behind inside the Ohio Union in Columbus, Ohio.
VIDEO: Anti-Trump protestor tackled while delivering speech in the Union pic.twitter.com/3ctSlWvgwW— The Lantern (@TheLantern) November 14, 2016
The protesters, using a bullhorn, said to the large crowd, "We don't have to compromise."
At the same time, a man in a scarlet and gray long-sleeved shirt with a baseball hat was seen sprinting down the stairs and shouting, "You idiot!"
Video showed the man smashing into the back of the protester, sending to protester falling down the stairs and onto the ground as the crowd gasped.
A man in a Guy Fawkes mask was seen jumping forward from the crowd to hit the attacker as police officers moved in to take the tackler away.
The crowd chanted "shame" as police led the suspect away.