Since leaving the Reagan administration, Gaffney founded the Center for Security Policy. When Donald Trump called for Muslims to be banned from entering the United States during the campaign, he cited a poll from the Center for Security Policy.
Gaffney is known for extreme anti-Muslim statements and has claimed that "creeping Sharia" poses a threat to the United States. He has accused members of the Obama administration of being part of the Muslim Brotherhood, specifically Hillary Clinton aide Huma Abedin. And he was also banned from the conservative CPAC conference for claiming that leaders of the conference were members of the Muslim Brotherhood. He has since returned to the conference.
He has also promoted the conspiracy theory that President Obama was not born in the U.S. and the Center for Security Policy has suggested that Obama is a Muslim.
The Southern Poverty Law Center describes Gaffney as "one of America’s most notorious Islamophobes."
Correction: This story originally said that Gaffney joined the Trump transition team, but reports only indicated that he has been advising Trump's team.