Years after the Rev. Terry Jones began making what were considered radical, xenophobic pronouncements about Muslims, those policy prescriptives now are a core element of Republican presidential candidate Donald Trump’s campaign. (Michael S. Williamson/The Washington Post)

As far as the Rev. Terry Jones knows, they were his ideas first.

“We are asking for the immediate halting of all Muslim immigration and the removal of all illegal aliens from the United States,” the controversial Florida pastor told a Detroit radio station back in 2011. “We are asking for the monitoring of all the mosques in America.”

At the time, Jones’s demands were dismissed as crazy, part of a set of radical beliefs and xenophobia that impelled Jones to publicly burn Qurans and air mocking videos that provoked violent attacks on embassies and consulates in Egypt, Afghanistan and Libya.

Four and a half years later, those policy prescriptives are a core element of Republican presidential candidate Donald Trump’s campaign.

The party’s standard-bearer has borrowed heavily both in message and in membership from far-right conservative activists whose pronouncements on Islam have long been denounced as dangerous zealotry by mainstream conservative and liberal policymakers alike.

In an election that has put American Muslims under the spotlight, three voters from different parts of the country reflect on how the political rhetoric has affected them. (McKenna Ewen,Whitney Leaming,Alice Li/The Washington Post)

Former president George W. Bush and GOP candidates Sen. John McCain (R-Ariz.) and Mitt Romney all repudiated anti-Islam rhetoric as un-American.

Trump has become the first and only major-party presidential candidate to adopt these ideas as his own. With his calls for a complete ban on Muslim immigrants or “extreme vetting” on people entering the country, policy prescriptives once relegated to the fringe have become mainstream.

The migration of anti-Islam extremist views to major-party acceptance is, like much in American politics, a fusion of opportunism and ideology. It often has been highly profitable for its practitioners as well.

In 2007, Brigitte Gabriel, a former reporter for Pat Robertson’s evangelical television channel and author of a book on the dangers of Islam, founded Act! for America, an organization that touted as its “first accomplishment” its 2008 campaign to shut down a Minnesota Islamic school.

That same year, former newspaper executive Pamela Geller used her increasingly popular libertarian blog AtlasShrugs.com to spread the falsehood during the 2008 presidential campaign that President Obama was born in Kenya and was a secret Muslim.

So did former Reagan administration aide Frank Gaffney Jr., whose neoconservative think tank argued that the country was at risk of falling victim to “civilization jihad” at the hands of the Muslim Brotherhood.

The Egypt-based Islamist movement, Gaffney alleged, harbored a sinister bid to destroy American society and implement Islamic law.

With the Obama rumors, Gaffney, Geller, Gabriel and others found a more direct way to advance a broader opposition to Islam — and a right-wing audience to embrace it. Along the way, Kellyanne Conway, now Trump’s campaign manager, contributed polling to sharpen the message.

By 2010, anti-Muslim activists had launched a nationwide media campaign against what they dubbed “the Ground Zero mosque,” a proposal to build a mosque and Muslim community center in Lower Manhattan. Act! for America convened its first “National Conference and Legislative Briefing” in Washington, which brought advocates together with lawmakers, including Rep. Peter T. King (R-N.Y.) and then-Rep. Michele Bachmann (R-Minn.).

Both went on to hold congressional hearings to examine militants infiltrating the country.

While most mainstream politicians continued to malign the activists — the Conservative Political Action Conference barred Gaffney from speaking in 2010 after he accused two of its members of working with the Muslim Brotherhood — they spread their ideas through a network of small conferences, tea party groups, conservative churches and Jewish groups, and right-wing news outlets such as Breitbart. Former Breitbart chief executive Stephen Bannon is now chief executive of the Trump campaign.

[Trump’s campaign chief faces scrutiny over voter registration, anti-Semitism]

They told their audiences that Islam isn’t a religion but a political ideology that is inherently violent and opposed to Judeo-Christian values. They warned that mosques and Muslims should be watched. And they argued that practicing Islam means belief in the oppression of women and the murder of infidels, and that the religion is therefore unconstitutional.

Most important of all, they said, was to stop the advance of what they labeled “creeping sharia,” an alleged Muslim plot to impose Islamic law across American institutions.

Sharia is not a codified document like the U.S. Constitution, say religious and legal scholars, but rather a broad and variably interpreted set of ideas and principles for how to live life as a Muslim. It offers an array of guidance, including on prayer practices, marriage, diet and finances. It also draws on tens of thousands of texts and scholarly interpretations, meaning that there is no universally approved body of Islamic law, said Intisar A. Rabb, an Islamic legal scholar at Harvard University.

In the summer of 2010, former House speaker Newt Gingrich (R-Ga.) offered a darker vision. In a speech at the American Enterprise Institute, he said sharia is “a mortal threat to the survival of freedom in the United States and the world as we know it.”

It was “the pre-eminent totalitarian threat of our time,” said Gaffney’s Center for Security Policy’s report, “Shariah — The Threat to America.” Among its authors were former CIA director James R. Woolsey and Joseph E. Schmitz, both of whom are now national security advisers for Trump.

The center’s general counsel, David Yerushalmi, drafted a law to ban sharia, and with the help of Act! for America began shopping the draft to lawmakers in Southern states.

Bills to ban sharia now have been introduced in all but 16 states. To date, Tennessee, Arizona, Kansas, Louisiana and South Dakota all have passed some form of legislation to ban “foreign law”— wording adopted in most cases to avoid an explicit violation of the Constitution, which prohibits the favoring or targeting of one religion. Alabama’s bill failed, but its voters banned sharia by ratifying a constitutional amendment.

Faiza Patel, the co-director of the Liberty and National Security Program at New York University Law School’s Brennan Center for Justice, said “the idea that sharia law poses a threat to the United States is just laughable.”

But it makes sense that sharia has worked as a focal point for the anti-Muslim movement. For many Americans, the definition offered by the activists was also their first introduction to the concept.

“The theory that ‘the Muslims are coming’ ” has helped anti-Muslim activists to “malign Muslim individuals and groups, and suggest that they have some sort of terrorist ties,” Patel said. “We’ve seen this with [longtime Hillary Clinton aide] Huma Abedin. And we’ve seen a concerted campaign against [Muslim lobbyist group] the Council on American-Islamic Relations for some time.”

The business of speaking out against Muslims also has been lucrative.

Seven charitable groups provided $42.6 million to “Islamophobia think tanks” such as those run by Gaffney and Gabriel between 2001 and 2009, researchers at the Center for American Progress found.

In 2014, Gaffney was paid more than $308,000, and Gabriel earned at least $240,000, according to the IRS Form 990 filed by their organizations.

The 2014 rise of the Islamic State, with its gruesome beheading videos, created new fears and gave the movement new energy.

The Islamic State was practicing Islamic law when it executed journalists and religious minorities, the anti-Islam activists told their audiences, and so were the gunmen who carried out the 2015 and 2016 terrorist attacks in Paris, Brussels, San Bernardino, Calif., and Orlando.

When the 2016 election cycle rolled around, not everyone in the movement rallied immediately around Trump. Some, including Gaffney, initially joined the campaign of Sen. Ted Cruz (R-Tex.), and Ben Carson also won support with references to “civilization jihad.”

But Trump ultimately incorporated the message into his presidential platform like no other major-party candidate had before.

In previous presidential campaigns, the Republican candidates “beat back” the movement’s conspiracy theories, said Ken Gude, a senior fellow at the Center for American Progress, who co-authored an updated report on the movement last year. “Now we have a campaign that not only isn’t pushing back against them, but is also pushing and advocating those kinds of views.”

Walid Phares, one of Trump’s foreign policy advisers, was part of a Lebanese Christian militia that took part in massacres during the Lebanese civil war and has previously accused the U.S. government of being beholden to an Islamist agenda. And another top adviser, retired Army Lt. Gen. Michael Flynn, joined the board of Act! for America shortly after joining the Trump campaign. Gingrich and Bachmann are also advisers.

[Michelle Bachmann under fire for Muslim Brotherhood claims]

But the “top expert with influence on these issues is Frank Gaffney, who advised Cruz, then provided research to Trump,” Phares wrote in an email. He also named Schmitz, Flynn, Gingrich and former New York mayor Rudolph W. Giuliani as key sources on developing policy ideas on Islam.

“A number of these folks are friends of mine,” Gaffney said in an interview about Trump’s inner circle. “I’ve had conversations with them, [and] the opportunity to provide input [to the campaign], at least informally.”

When Trump in December first called for a “total and complete shutdown of Muslims entering the United States,” he cited a widely debunked poll , conducted by Conway for Gaffney’s Center for Security Policy, that claims that 25 percent of Muslims surveyed supported violence against Americans and that 51 percent think Muslims should have the choice of being governed by sharia in America.

[The Fix: The very bad poll at the center of Trump’s proposed Muslim ban]

A large number of Americans have long recognized “the jihad threat,” and Trump is giving voice to those sentiments, Geller said. It’s only the mainstream media, “a Soros-funded propaganda arm for the far-Left and its Islamic supremacist allies,” she said, that has stood in the way of broader acceptance.

On the campaign trail, where Trump warns repeatedly of the dangers posed by Muslims, the candidate is articulating, Gaffney said, “the most serious and thoughtful and necessary policy toward the threat that we face from the global jihad movement of anybody in public life at the moment.”

“Anyone who believes sharia law supplants American law will not be given an immigrant visa,” Trump said at an August campaign rally in North Carolina. The crowd shouted its response: “U.S.A.! U.S.A.!”

Alice Crites contributed to this report.