But several reporters from a Montana TV station said it was Gianforte who grabbed Jacobs and threw him to the ground, breaking the reporter's glasses, as Jacobs was trying to ask the Montana Republican a question following a television interview.
After audio emerged of the altercation - and after Gianforte had won the special election - the Republican Congressman plead guilty to a charge of misdemeanor assault, and was sentenced to community service and anger management.
Jacobs had been asking Gianforte about health care policy, and what Republicans would do in their bid to repeal and replace the Obama health law, something the GOP Congress was ultimately unable to achieve in 2017 and 2018.
Earlier at the campaign rally, President Trump had repeatedly accused Democrats of using 'mob' tactics and 'mob rule' to try to intimidate Republican candidates and GOP voters in the November mid-term elections.
"Democrats produce mobs. Republicans produce jobs," the President said to cheers.
"The President of the United States tonight applauded the assault on an American journalist," said Guardian US Editor John Mulholland in a written statement issued after the event.
"In the aftermath of the murder of Jamal Khashoggi, it runs the risk of inviting other assaults on journalists both here and across the world where they often face far greater threats," Mulholland added, as he called for Mr. Trump to apologize.
"He is literally cheering beating the crap out of the press," said Sen. Chris Murhpy (D-CT). "Good god."