United States House of Representatives
Representative Barbara Cubin, whom Lummis had supported during the 1994 election, announced that she would not run for reelection in the 2008 election. On January 2, 2008, Lummis announced that she would run for Cubin's seat, winning the Republican nomination against Mark Gordon, Bill Winney, and Michael Holland, having challenged them to debates held in all 23 Wyoming counties during the primaries. A poll conducted from January 18 to 21 showed that Lummis had a favorability rating of 29%, an unfavorability rating of 17%, and a neutral rating of 24%; 30% did not recognize her. Tucker Fagan, who later served as her chief of staff, served as Lummis's campaign manager. During the campaign Rachael Seidenschnur, her press secretary, resigned after using a fake name to ask Lummis's opponent a question. She defeated Democratic nominee Gary Trauner in the general election. During the campaign Lummis raised $1,557,313 and spent $1,543,875 while Trauner raised $1,672,707 and spent $1,716,013.
Lummis was reelected in 2010 against Democratic nominee David Wendt and Libertarian nominee John V. Love, after having raised $780,426 and spending $754,270 compared to Wendt, who had raised $65,709 and spent $68,523 On May 12, 2012, Lummis announced that she would run for reelection. She was reelected in the 2012 election over Democratic nominee Chris Henrichsen after having raised $715,314 and spent $631,026. She was reelected in the 2014 election against Democratic nominee Richard Grayson, after having raised $432,666 and spent $300,949.
On November 12, 2015, Lummis announced that she would not seek reelection in the 2016 election. Liz Cheney was elected to succeed her. Lummis's daughter, Annaliese Wiederspahn, served as Leland Christensen's campaign manager during the Republican primary. Lummis considered running for the Republican nomination in the 2018 gubernatorial election, but declined to run, instead endorsing Sam Galeotos. She sought a position in President Donald Trump's cabinet by attempting to replace Ryan Zinke as United States Secretary of the Interior, but David Bernhardt was appointed instead.
During Lummis's tenure in the House, she served on the Agriculture and Appropriations Committees and on the Energy and Mineral Resources, National Parks, Forests and Public Lands, and Energy and Water Development Subcommittees. She was the first representative from Wyoming to serve on the Agriculture Committee since Frank O. Horton, who served on the committee from 1939 to 1941. In 2011, she was appointed vice chair of the Appropriations Subcommittee of the Agriculture Committee. Lummis left the Appropriations Committee in 2013, saying she had requested her removal from the committee and that it was not part of a purge of radical Republicans from committee positions. She was appointed chair of the Science Subcommittee on Energy in 2013.
Lummis served as the communications chair and spokesperson of the Congressional Western Caucus and succeeded Dean Heller as vice chair in 2011 following Heller's appointment to the United States Senate. Lummis was elected to serve on the House Republican Steering Committee in 2010. She was at one point the only female member of the Freedom Caucus and the last until the election of Debbie Lesko. Lummis co-chaired the Congressional Caucus for Women's Issues alongside Representative Gwen Moore from 2011 to 2013. She was also a member of the Tea Party Caucus.
Lummis supported Speaker John Boehner while the Freedom Caucus successfully pushed to remove Boehner. She praised the election of Paul Ryan as Speaker, saying, "we have ushered in thoughtful, conservative leadership, restored member-driven policy-making to the legislative process and returned regular order that will bring sunshine to back rooms making government work better".
Lummis served on the Republican whip team until she was removed from the position in 2015, for voting against giving President Barack Obama the authority to propose a trade agreement with Pacific countries. She said she knew she would be removed from her position on the whip team for her vote but did not regret it. Representatives Steve Pearce and Trent Franks were also removed from the whip team for their votes.
During the 2008 presidential election, Lummis was supposed to give a speech at the Republican National Convention on the first day, but her speech was canceled due to Hurricane Gustav. During the 2012 Republican presidential primaries she endorsed Mitt Romney and served as the chair of Romney's campaign in Wyoming. During the 2016 Republican presidential primaries, she was a campaign surrogate for Rand Paul, and later endorsed Trump in the presidential election.
