Sporting a "Make America Great Again" cap, the man shoved and swore at the BBC's Ron Skeans and other news crews before being pulled away at the rally at El Paso on Monday night.
Skeans said the "very hard shove" came from his blindside. "I didn't know what was going on."
Skeans said the man almost knocked him and his camera over twice before he was wrestled away by a blogger.
Trump saw the attack and confirmed Skeans was well with a thumbs up after it happened. He continued his speech after Skeans returned the gesture, the BBC said.
A campaign official suggested the attacker was drunk.
O'Donoghue added that he had been "spat at before".
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)