Since 1998, Simpson has been known as a moderate Republican. For example, he has supported the
National Endowment for the Arts and the
National Endowment for the Humanities, voting each year against Republican amendments to strip them of funding. In the past he has opposed
earmarks.
Esquire listed Simpson as one of the 10 best members of Congress in October 2008. The magazine wrote, "More than any other representative, Simpson lives by the philosophy that democratic representation is a matter of finding not advantageous positions but common ground". Simpson played a key role in the election of
John Boehner as
House majority leader in the
109th United States Congress. He was close and loyal to Speaker
John Boehner.
Donald Trump During the
2016 U.S. presidential election, Mike Simpson declined to endorse Donald Trump, the only Republican in
Idaho's congressional delegation to do so. Simpson called him "unfit to be president," and later stated he would not vote for Trump in the general election, a departure from other Idaho Republicans such as
Jim Risch,
Mike Crapo, and
Raúl Labrador who backed Trump. After the
firing of FBI Director
James Comey, Simpson said he'd believe Comey's version of events over Trump's. Simpson was one of few Republicans calling for an independent commission to look into the
ties between the president and Russia. In 2025, Simpson called for renaming the Opera House at the John F. Kennedy Center for the Performing Arts after first lady Melania Trump. The editorial board of the
Idaho Statesman described the move as sycophantic.
Immigration In 2021, Simpson was one of 30 Republicans who voted for the Farm Workforce Modernization Act, which would grant legal status to certain
illegal immigrants working in agriculture and establish a pathway to
permanent residency contingent on continued farm work. Simpson voted for the Further Consolidated Appropriations Act of 2020, which authorized DHS to nearly double the available H-2B visas for the remainder of FY 2020. Simpson voted for the Consolidated Appropriations Act (H.R. 1158). Simpson supports
Deferred Action for Childhood Arrivals (DACA).
LGBT rights In 2021, Simpson was among the House Republicans to sponsor the Fairness for All Act, the Republican alternative to the Equality Act. The bill would prohibit discrimination on the basis of sex, sexual orientation, and gender identity, and protect the free exercise of religion. In 2021, Simpson was one of 29 Republicans to vote to reauthorize the
Violence Against Women Act. This bill expanded legal protections for transgender people and contained provisions allowing transgender women to use women's shelters and serve time in prisons matching their gender identity. In 2022, Simpson was one of 47 House Republicans to vote with the Democratic Party for the
Respect for Marriage Act, repealing the
Defense of Marriage Act. He later voted for the final form of the bill as passed in the Senate in December.
Jim Jordan speaker nomination After the
removal of
Kevin McCarthy as
Speaker of the House, Simpson was
one of 18 Republicans who voted against
Jim Jordan, who had been endorsed by
Donald Trump, in all three ballots for Speaker of the House. This prompted sharp criticism from the
Idaho Republican Party, which said it had been “inundated” with complaints from voters and accused Simpson of aligning with Democrats and failing to represent the priorities of Idaho constituents
Judgeships Simpson has pushed to divide the
United States Court of Appeals for the Ninth Circuit, sponsoring bills to that effect in 2007, 2011, 2017, and 2021. None of these bills were successful. In 2010, Simpson joined congressman
Walt Minnick in his effort to secure a third federal judge for Idaho. Simpson said, "The caseload of the Idaho District Court has increased significantly in recent decades resulting in Idaho's district judges carrying a disproportionate share of cases in relation to their colleagues in other states." As of May 2024, Idaho still has
two federal judgeships.
2020 election In December 2020, Simpson was one of 126 Republican members of the
House of Representatives to sign an
amicus brief in support of
Texas v. Pennsylvania, a lawsuit filed at the
United States Supreme Court contesting the results of the
2020 presidential election. The Supreme Court declined to hear the case on the basis that Texas lacked
standing under
Article III of the Constitution to challenge the results of an election held by another state. In January 2021, Simpson voted to certify both Arizona's and Pennsylvania's results in the
2021 United States Electoral College vote count. On May 19, 2021, Simpson was one of 35 Republicans to join all Democrats in voting to approve legislation to establish the
January 6 commission meant to investigate the
attack of the U.S. Capitol.
Health care Simpson has committed to repealing the
Affordable Care Act (also known as Obamacare), questioning its constitutionality and effectiveness. In 2014, Simpson was an original co-sponsor of the
Newborn Screening Saves Lives Reauthorization Act of 2013 (H.R. 1281; 113th Congress), a bill that would amend the
Public Health Service Act to reauthorize grant programs and other initiatives to promote expanded
screening of newborns and children for heritable disorders. In 2017, Simpson voted for and presided over the vote on the
American Health Care Act of 2017.
Tax reform Simpson supports
tax reform. When asked about the
Grover Norquist pledge to oppose any net increase in taxes, Simpson said, "Well, first, the pledge: I signed that in 1998 when I first ran. I didn't know I was signing a marriage agreement that would last forever." Simpson voted for the
Tax Cuts and Jobs Act of 2017.
Climate change In a 2019 conference in Boise, Simpson said: "climate change is a reality. It’s not hard to figure out. Go look at your thermometer." In his speech, he tied climate change to the viability of salmon in Idaho lakes and rivers.
Energy Simpson is a support of
nuclear power, extolling its virtues as an environmentally friendly source of energy with minimal carbon output. His support for nuclear energy plays a significant role in his membership of the
United States House Appropriations Subcommittee on Energy and Water Development, which oversees the
Idaho National Laboratory, a main site for nuclear and
alternative energy research in the United States. On June 20, 2014, Simpson introduced the
Energy and Water Development and Related Agencies Appropriations Act, 2015 (H.R. 4923; 113th Congress), a bill that would make
appropriations for energy and water development and related agencies for FY2015. The bill would appropriate $34 billion, which is $50 million less than these agencies then received. The appropriations for the
United States Department of Energy and the
United States Army Corps of Engineers are made by this bill.
Ukraine In 2022, Simpson voted to provide approximately $14 billion to the
government of Ukraine.
Social issues Simpson supports efforts to make it illegal to desecrate the
American flag.
Abortion Simpson is
anti-abortion. He has a zero rating from
NARAL Pro-Choice America and a 100% rating from the
National Right to Life Committee for his voting record on
abortion. He opposes using federal monies to fund abortions,
embryonic stem cell research, restricting the transport of minors over state lines to receive abortions,
partial-birth abortions except to save a mother's life and
human cloning. He supports cutting federal funding of
Planned Parenthood.
Big Tech In 2022, Simpson was one of 39 Republicans to vote for the
Merger Filing Fee Modernization Act of 2021, an antitrust package that would crack down on corporations for anti-competitive behavior.
Pesticides Simpson sponsored (
Department of the Interior, Environment, and Related Agencies Appropriations Act, 2026) which would shield pesticides makers including
Bayer by not allowing
glyphosate to be labeled under the
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) as
carcinogenic. This would end
lawsuits against Monsanto which often allege that a lack of cancer warning amounts to mislabeling under FIFRA. ==Election results==