Greg Gianforte, the Republican congressional candidate from Montana who had a physical altercation Wednesday with a journalist, is a tech entrepreneur and multimillionaire who sold his self-made company RightNow Technologies to Oracle in 2012.
He's estimated to have spent more than $5.1 million of his own money on an unsuccessful gubernatorial campaign in 2016.
He's running against Democratic candidate Rob Quist for the state's lone congressional seat and has outraised Quist $1.6 million to just shy of $1 million in the first quarter, which ended March 31.
The special election for that seat, which was vacated by Republican Ryan Zinke upon his appointment to US secretary of the interior, will be held Thursday.
The Trump administration has lent plenty of support to Gianforte.
President Donald Trump's son, Donald Trump Jr., and Vice President Mike Pence both have campaigned for Gianforte.
The President is helping with a robocall.
"Hi, this is President Donald Trump and I know what the people of Montana really want and really care about," Trump said in the robocall. "If you don't vote tomorrow, the liberal Democrats running for Congress will decimate and dismantle all that we've done. ... So get to the polls and vote for Greg. That's Greg Gianforte, you'll be very proud of him for years to come. Thanks a lot!"
The altercation took place Wednesday at Gianforte's campaign headquarters in Bozeman.
Gianforte, 56, allegedly body slammed Ben Jacobs, a reporter for The Guardian, and broke his glasses, according to an audio recording of the event and eyewitness accounts.
"He took me to the ground," Jacobs said.
But Gianforte's campaign said Jacobs acted aggressively toward the candidate, shoved a recorder into his face, grabbed him by the wrist and pulled them both to the ground.
The Gallatin County Sheriff's Office said it was conducting an ongoing investigation into "allegations of an assault involving Greg Gianforte," but didn't provide further details.