The Democratic Congressional Campaign Committee and MoveOn.org used the Wednesday night incident, involving reporter Ben Jacobs of The Guardian, in online and radio ads to spur last-minute voter registration and turnout.
By the time news of the incident broke, even though it was the day before the special election, Gianforte likely had already secured his victory.
The race is seen as a test of Trump's political clout ahead of next year's congressional elections. He ended up winning the special election, but before that was determined, late-night hosts weighed in on the alleged assault.
Ryan would not say whether he and fellow House Republican leaders would agree to seat Gianforte should the candidate win but the Speaker suggested that the wishes of Montana voters would be respected.
Greg Gianforte was the victor in Thursday's congressional election in Montana. I will tell you that it's unacceptable behavior and to say otherwise would be false, obviously.
The Gallatin County Sheriff's office later charged Gianforte with misdemeanor assault.
Despite the loss, the results do show a gain for Democrats in Montana, after their 2016 candidate picked up only 40.5% of the vote against Zinke.
"I should not have responded the way I did, and for that I'm sorry", Gianforte said.
In an audio recording posted by The Guardian, an agitated Gianforte brushes off Jacobs' question - right before there's a giant crashing noise and the apparent sound of the two men scuffling.
Trump and Vice President Mike Pence recorded robocalls urging voters not to let the Democrats take the seat. And for that, I'm sorry, Mr. His win came one day after Gianforte was charged for assaulting a reporter.
Gianforte's victory is a boost for Republicans, who are anxious Trump's political stumbles and the unpopularity of the healthcare bill passed by the House will hurt their chances of holding on to a 24-seat House majority in next year's elections. Quist: a first-time candidate and Montana folk singer who'd amassed moderate Montana fame in the 1970s as a member of the Mission Mountain Wood Band. Several news outlets called the race by early Friday morning, including the Associated Press and CNN. Quist raised $6 million, and progressive groups like Democracy for America enlisted thousands of people to make hundreds of thousands of phone calls on Quist's behalf. Screnar said she and her husband have known Gianforte for the better part of a decade.