The Center made this argument in depth in a 2015 report it called “The Secure Freedom Strategy: A Plan for Victory Over the Global Jihad Movement.” Fleitz was one of its 16 co-authors. It called for revoking the citizenship of American Muslims who follow Islamic law. The government, it argued, should “use shariah-adherent advocacy and practices as legal premises for deportation and stripping of American citizenship.” It “must revoke the citizenship of naturalized Americans who, in seeking to insinuate shariah-compliant norms into civil society, have violated their oath of naturalization and allegiance to defend the Constitution of the United States.”

The report did not stop there. “Over 80 percent of U.S. mosques have been shown to be shariah-adherent,” it declared, “as evidenced in such visible characteristics as dress, beards, and male-female segregation; the content of preaching and sermons; and printed materials on display or for sale. They are incubators of, at best, subversion and, at worst, violence and should be treated accordingly.” To understand what the report means by “treated accordingly,” it’s worth noting that Gaffney has cited the 80-percent figure as evidence that the residents of Murfeesboro, Tennessee, should be allowed to block the construction of a mosque in their town.

The report argues that, in seeking to replace the Constitution with shariah law, these mosques are part of a conspiracy led by the Muslim Brotherhood, which also secretly controls some of America’s largest Muslim communal organizations, including the Council on American Islamic Relations, the Islamic Society of North America, and the North American Islamic Trust. The report proposes “new legislation that identifies and bans Brotherhood operations” like these “as hostile or subversive to the U.S. legal order.” If that’s not possible, it continues, “at a minimum,” the government should revoke their tax-exemptions since “501(c)(3) status … should be reserved for those institutions not promoting shariah in any way.” The report also urges that America’s “academic institutions” “be discouraged” from supporting “interfaith dialogue, ‘Muslim-Christian understanding,’” and other programs aimed at promoting tolerance between Muslims and non-Muslims because such work often “amounts to promoting shariah.”

Not long ago, views like this made Gaffney and the Center for Security Policy pariahs in conservative Washington. In 2011, after Gaffney accused the anti-tax activist Grover Norquist of “supporting a stealthy effort to bring shariah” to the United States, the American Conservative Union informally banned him from speaking at its signature event, the Conservative Political Action Conference (CPAC). In 2013, Gaffney lost his longtime column at The Washington Times. In 2015, The Daily Beast observed that, “Gaffney has been shunned by pretty much everyone in conservative intellectual circles.”