In 2012, Congresswoman Michelle Bachmann made her own foray into Islamophobia by signing a letter, along with four House Republican colleagues, demanding an investigation into Hillary Clinton’s Muslim aide Huma Abedin. John McCain responded by going to the Senate Floor to declare that the assault on Abedin “is not only wrong; it is contrary to everything we hold dear as Americans.” House GOP leader John Boehner called the attacks “dangerous.” Ed Rollins, Bachmann’s own former campaign chairman wrote an oped on foxnews.com that concluded, “Shame on you, Michele! You should stand on the floor of the House and apologize to Huma Abedin and to Secretary Clinton and to the millions of hard working, loyal, Muslim Americans for your wild and unsubstantiated charges.” That was only five years ago.

Then it was Ben Carson’s turn. In September 2015, the surgeon turned presidential hopeful said, “I would not advocate that we put a Muslim in charge of this nation” because Islam was not “consistent with the Constitution.” The media responded by asking Carson’s rivals for comment, and most of them—even social conservative hardliners like Ted Cruz and Mike Huckabee—said they disagreed.

But then something interesting happened. Unlike Cain, Carson refused to apologize. Instead, he attacked the media and the left. Carson’s business manager, Armstrong Williams, declared on CNN’s morning show that his boss would continue “telling the truth, even if it makes CNN and others uncomfortable.” Carson’s campaign manager Barry Bennett crowed that, “While the left is huffing and puffing, the Republican primary voters are with us at least 80-20.” Donald Trump went even further. Asked by NBC’s Chuck Todd whether “putting a Muslim in the White House” is okay, Trump responded that, “some people have said it already happened.”

What changed between 2012 and 2015? Part of the answer is ISIS. Between 2014 and 2015, the group’s capture of Mosul, followed by a series of beheadings covered lavishly by the American media, produced a spike in fear of jihadist terrorism, especially on the right. Between 2014 and 2015, according to the Chicago Council of Global Affairs, the percentage of Republicans calling “Islamic fundamentalism” a “critical threat” jumped almost twenty points. Between 2010 and 2015, according to a poll by the Arab American Institute, favorable attitudes toward American Muslims fell 15 points. By December 2015, after the attacks in Paris and San Bernardino, Americans were more afraid of terrorism than at any point since the immediate aftermath of 9/11.

Another part of the answer is the declining influence of traditional GOP elites. Days after Carson’s comments about a Muslim president, John Boehner—who had denounced Bachmann’s Islamophobia—stepped down as House Minority Leader. John McCain, who had also condemned Bachmann, was by 2015 so diminished among GOP voters that Trump could mock him for being captured in Vietnam and continue rising in the polls.