2006 United States House of Representatives election in Montana

The Republican Party, also referred to as the GOP, is one of the two major contemporary political parties in the United States. The GOP was founded in 1854 by anti-slavery activists who opposed the Kansas–Nebraska Act, which allowed for the potential expansion of chattel slavery into the western territories. It has been the main political rival of the Democratic Party since the mid-1850s. Like them, the Republican Party is a big tent of competing and often opposing ideologies. Presently, the Republican Party contains prominent conservative, centrist, populist, and right-libertarian factions.

Dennis Ray Rehberg is an American politician and member of the Republican Party. He served as the Lieutenant Governor of Montana from 1991 to 1997 and as the U.S. representative for Montana's at-large congressional district from 2001 to 2013. Rehberg was the Republican nominee for the United States Senate in 1996 and 2012, losing to Democratic incumbents Max Baucus 50% to 45% and Jon Tester 49% to 45%, respectively. He subsequently became a co-chairman at Mercury, a Washington D.C. lobbying firm.

The Democratic Party is one of two major contemporary political parties in the United States. Founded in 1828, it was predominantly built by Martin Van Buren, who assembled politicians in every state behind war hero Andrew Jackson, making it the world's oldest active political party. Its main political rival has been the Republican Party since the 1850s, with both parties being big tents of competing and often opposing viewpoints. Modern American liberalism — a variant of social liberalism — is the party's majority ideology. The party also has notable centrist, social democratic, and left-libertarian factions.

Monica Lindeen is an American politician who served as the Montana State Auditor. She was elected in 2008 and re-elected in 2012. Due to term limits, she was ineligible to run again in 2016, and became a candidate for Montana Secretary of State.

The Libertarian Party (LP) is a political party in the United States that promotes civil liberties, non-interventionism, laissez-faire capitalism, and limiting the size and scope of government. The party was conceived in August 1971 at meetings in the home of David F. Nolan in Westminster, Colorado, and was officially formed on December 11, 1971, in Colorado Springs, Colorado. The organizers of the party drew inspiration from the works and ideas of the prominent Austrian school economist, Murray Rothbard. The founding of the party was prompted in part due to concerns about the Nixon administration, the Vietnam War, conscription, and the introduction of fiat money.