Montana is holding a special election on Thursday for the state's congressional seat. Here are some key points about what's going on.
Why is a special election being held?
Ryan Zinke left Montana's seat in the House of Representatives vacant when he resigned to join President Donald Trump's cabinet. Zinke currently serves as the president's secretary of the Interior Department.
Who is running in the special election?
The ballot will include three candidates: Republican Greg Gianforte, Democrat Rob Quist, and Libertarian Mark Wicks.
Both Trump and Vice President Mike Pence recorded robocalls in support of Gianforte.
Sen. Bernie Sanders, a 2016 Democratic presidential candidate, has campaigned for Quist.
What is the controversy over Gianforte?
Gianforte has been charged with misdemeanor assault, after he allegedly grabbed Ben Jacobs, a reporter for The Guardian, by the neck and threw him to the ground.
Gianforte was getting ready for an interview with Fox News Wednesday when Jacobs walked into the office. Jacobs pressed Gianforte about the GOP health care bill before being slammed to the ground and punched, Fox News reporter Alicia Acuno wrote.
"To be clear, at no point did any of us who witnessed this assault see Jacobs show any form of physical aggression toward Gianforte, who left the area after giving statements to local sheriff's deputies," she said in her account.
What has the Gianforte campaign said?
The Republican hopeful's campaign has blamed Jacobs, saying the reporter was being "aggressive" and grabbed Gianforte.
"After asking Jacobs to lower the recorder, Jacobs declined," a campaign spokesman said in a statement. An audio recording from The Guardian of the incident doesn't include Jacobs being asked to lower the device.
What about Jacobs' take?
Jacobs claimed he never touched Gianforte before he was thrown to the ground.
Jacobs was doing his job and asking a question of Gianforte as part of covering Thursday's special election, he told "Good Morning America."
"The only thing that is factually correct ... is my name and place of employment," Jacobs said of Gianforte's account.
What has the reaction been?
Newspapers the Billings Gazette, the Independent Record, and the Missoulian have rescinded their endorsements of Gianforte.
The Democratic Congressional Campaign Committee has also called for Gianforte to withdraw his candidacy.
What about Quist's financial troubles?
His campaign filed a new disclosure statement with the U.S. House after The A.P. sought an explanation for discrepancies in his initial disclosure document and on his 2016 income tax returns. Federal ethics law requires congressional candidates to file a one-time accounting of their personal finances.
The updated disclosure was routine, a Quist spokeswoman said. She asserted that Quist and his wife did not have a full accounting of their income when he completed his initial report.
There have also been revelations that Quist defaulted on a $10,000 bank loan, failed to thousands of dollars to a contractor he hired, and faced three tax liens over $15,000 in unpaid back taxes.
The liens covered 2007, 2011, and 2012, and were settled in May 2016. Quist has not shared tax returns for those years.
The Associated Press contributed to this report.