He served as a
trustee on
Fabius Township Board in
St. Joseph County, Michigan, from 1972 to 1976 and also worked as a real estate broker. At the time of Siljander's election,
Michigan's 4th congressional district covered southwestern Michigan and included
Three Rivers and
Kalamazoo.
Time magazine noted that the district was predominantly conservative, having elected only one Democrat in [the twentieth] century, in 1932. Siljander was known as a dogmatic
social conservative. He criticized President
Ronald Reagan's appointment of
Sandra Day O'Connor to the Supreme Court, viewing her track record as insufficiently conservative.
Time described him as a
fundamentalist Christian. During his race, Siljander expressed opposition to the
Equal Rights Amendment,
pornography,
abortion,
school busing and "big spending", as well as support for the
neutron bomb, the
MX missile and
prayer in public schools. ;1981 On January 27, 1981, incumbent Congressman
David Stockman resigned to serve as the director of the
Office of Management and Budget in the
Reagan administration. In the following special Republican primary, Siljander ranked first in a seven-candidate field with a plurality of 37%. He defeated Stockman-endorsed tax attorney John Globensky (36%) and State Senator John Mowat (22%). In the April 1981 special general election, he defeated Democratic
Cass County Commissioner Johnie Rodebush 69%-29%. In 1981, Congress enacted an amendment, named after Representative Mark Siljander, to the FY1982 Foreign Assistance and Related Programs Appropriations Act specifying that no U.S. funds may be used to lobby for abortion. Congress subsequently modified the amendment to state that funds may not be used to "lobby for or against abortion" ;1982 Siljander was challenged in the next Republican primary by attorney Harold Schuitmaker and defeated him 56%-44%. In the general election, he won re-election to a full term with 60% of the vote. ;1984 Siljander was challenged again in the Republican primary, and defeated Tim Horan 58%-42%. In the general election, he won re-election to a second full term with 67% of the vote. In 1984, Siljander sponsored a single-sentence amendment which read, "For the purposes of this Act, the term 'person' shall include unborn children from the moment of conception."
Alexander Cockburn referred to the Siljander Amendment as "the most far-reaching of all the measures dreamed up by the conservative right to undercut
Roe v. Wade." It failed 186–219. Siljander travelled with Christian Watch International to Romania in response to the growing concerns over religious minority persecution.
1985 Siljander proposed legislation which would deny
most favored nation status to countries that discriminate on cultural, ethnic or religious grounds. ;1986 Once again Siljander was challenged in the Republican primary, this time by
Fred Upton, a staffer to Stockman. Upton defeated Siljander 55%-45%, becoming the only Republican to unseat an incumbent in a primary that year.
Later career Siljander was appointed by President Reagan as an alternate representative to the
United Nations General Assembly, serving from September 1987 to September 1988. In the Republican primary, Siljander came in second to
Henry N. Butler, a
law professor at
George Mason University. Siljander co-founded the
Alliance Defending Freedom (ADF); ADF lawyers later wrote the model for Mississippi's anti-abortion legislation, leading to the Supreme Court decision in Dobbs v. Jackson Women's Health Organization to overrule
Roe v. Wade in 2022. Siljander is the president of Bridges to Common Ground. He also founded Trac5, with the stated goal to implement faith-based diplomacy in real-world conflicts Siljander's book, ''A Deadly Misunderstanding: A Congressman's Quest to Bridge the Muslim-Christian Divide'' was a 2009 Nautilus Silver Award Winner, and has a foreword written by
UN Secretary-General Ban Ki-moon, with whom Siljander worked closely to resolve the humanitarian disaster in Darfur. In Ban Ki-moon's book published in 2021 in a chapter titled "The Breakthrough", Moon recounts Siljander's involvement in resolving the Darfur crisis stating, "...Siljander prayed aloud, passionately for peace in Sudan. That night Siljander convinced President Omar al-Bashir to work closely with the United Nations." Siljander was featured in the 2019
Netflix miniseries
The Family, which details the history and activities of
The Fellowship, a secretive Christian organization with ties to politicians and world leaders. In the series, Siljander recounts his efforts to engage Muammar Gaddafi and help bring the Pan Am Flight 103 Lockerbie bombing terror suspects to justice. In 2020,
Pro-life Members of Congress led by
Senator Lankford used the Siljander Amendment to Prevent US from Funding Abortions, Abortion Advocacy Abroad. In 2025, Mark Siljander was featured on the
Jordan Peterson podcast which covered topics ranging from Islam, linguistic studies of the
Aramaic language of Jesus, and its application in international peacemaking.
Criminal conviction and pardon On January 16, 2008, Siljander was
indicted in the
federal district court in the Western District of Missouri on five counts including
money laundering,
conspiracy and
obstruction of justice. Siljander initially pleaded not guilty, but on July 7, 2010, as part of a
plea agreement, Siljander pleaded guilty to obstruction of justice and acting as an
unregistered foreign agent. On January 12, 2012, he was sentenced to a
year and a day in prison. The group for which Siljander worked as an unregistered foreign agent was the
Islamic American Relief Agency, a
Columbus, Missouri-based charity, which hired Siljander in early 2004 to lobby to get IARA removed from a
Senate Finance Committee list of charities suspected of funding international terrorism. IARA closed in October 2004 after it was added to the Treasury Department's list of
global terrorist organizations. During Siljander's sentencing, U.S. District Judge
Nanette Kay Laughrey stated that: ..."[U]nder the circumstances of this case there was no specific harm by the lobbying efforts that you undertook... The truth is, when you look at this objectively, this is not a case about somebody aiding a terrorist, it just isn't, and it would be wrong of me to, in fact, try to make it out to be that." In December 2020, President
Donald Trump pardoned Siljander, praising his pro-life record while a congressman and his post-prison work abroad. Trump's decision to pardon Siljander was criticized by Republican Congressman
Fred Upton, who succeeded Siljander after defeating him in the 1986 Republican primary. His pardon was supported by
Edwin Meese,
Newt Gingrich,
Mike Huckabee,
Robert Aderholt, and
Andrew Brunson. ==References==