Update, July 15: On Thursday night, Newt Gingrich proposed screening Muslims living in America to see whether or not they supported sharia law. In light of that, we're republishing this article from January explaining how sharia law became an issue of concern in American politics -- and how Gingrich himself played a role.

At a campaign stop in Fort Dodge, Iowa, this week, Sen. Marco Rubio (R-Fla.) was asked about keeping sharia law out of the United States. "Guys," he replied, according to the New York Times' Jeremy Peters, "that's not going to happen."

That question, or some variant thereof, has regularly been part of the political conversation in the United States for several years now. The idea that there will be a formal or informal shift in the country to sharia law — generally understood to be a system of restrictive legal guidelines used by Muslims — has gripped a segment of the electorate (mostly on the conservative side) and prompted political responses.

Rubio dismisses the idea that there would be some sort of transition to the theoretical precepts of sharia, no doubt in part because the United States has a well-defined legal structure already in place. But why was it even asked? How did the idea trickle down to a random voter in Iowa?

In May 1997, Newt Gingrich, then House speaker, argued from the chamber floor that the persecution of Christians around the world was "one of today's overlooked tragedies." He entered into the record a column from the Times' A. M. Rosenthal the month before. Rosenthal wrote about persecution of Christians in Asia and Africa, isolating the effort to mandate Islamic law in some places.

In the U.S., a coalition of 60 human rights and ethnic organizations watches out for persecution of minorities under ''Islamization.'' The coalition's definition is a political and cultural process to establish Islamic law, the sharia, as the ruling principle of all society, to which all must conform.

Sharia law was Islamization, and it was a threat to Christians.

Thirteen years later, in 2010, Gingrich again referred to sharia, this time after it had gained traction on the right and this time speaking as an eventual candidate for the Republican presidential nomination, not as an elected official.

"America is at risk," Gingrich said in a speech at the American Enterprise Institute. "This is a very important debate to have, because many of our elites are sleepwalking, as though we are managing at the margins. Trivial problems." The risk, in his estimation, was that radical jihadists were using "stealth" methods — "cultural, intellectual, and political" — to undermine the United States. This included sharia.

"The fight against sharia and the madrassas and mosques which teach hatred and fanaticism," he said, "is the heart of the enemy movement from which the terrorists spring forth. … One of the things I am going to suggest today is a federal law which says no court anywhere in the United States under any circumstance is allowed to consider sharia as a replacement for American law."

During that 13-year interval during which Gingrich moved from expressing worry about Christians in Africa to campaigning against the threat of sharia in the United States, three important things happened: 9/11, the Internet and Glenn Beck.

The attacks of Sept. 11, 2001, helped propel the idea that there were secret cells of terrorists living in the United States, as well as increasing skepticism of Muslims in general. The New York Police Department was surveilling mosques in an (ultimately futile) attempt to root out possible terrorists. The hunt was on for al-Qaeda leader Osama bin Laden, with American troops on the ground in Afghanistan and then Iraq. And politicians focused on national security.

In 2003, the Republican-led Senate Judiciary Committee held a series of hearings on the threat of terrorism in the United States, including one in October titled, "Terrorist Recruitment and Infiltration in the United States: Prisons and Military as an Operational Base." At that hearing, Michael Waller of the Institute of World Politics testified. He noted that a number of military chaplains had been trained at the Graduate School of Islamic and Social Sciences, thanks to the advocacy of a man who, Waller said, was a member of the Muslim Brotherhood, an organization that "works toward creating a world pan-Islamic state with a government based on Muslim sharia law."

The alleged role of purported members of the Muslim Brotherhood in attempting to subvert the government became a recurrent theme over the next decade. Frank Gaffney, founder of an organization called the Center for Security Policy (with which Waller was associated), has repeatedly implied links between prominent people and the Brotherhood. Among those it accused of ties to the group was prominent conservative Grover Norquist, who Waller claims was meeting with it on 9/11. (He claims to have discovered this by eavesdropping from an adjoining conference room.) The claim is generally dismissed on the right and led to Gaffney being barred from a conservative event a few years ago, and Norquist vehemently denies it. It was a highly questionable Center for Security Policy survey, you might recall, that became an argument used by Donald Trump in his recent call to suspend migration to the United States by Muslims.

Assessments of the spread of Islamic law internationally, similar to that Rosenthal article cited by Gingrich, continued. Stories about instances in which Muslims sought to uphold tenets of their faith in Europe appeared regularly, as did news reports about acceptance of sharia law internationally. In the post-9/11 world, those stories took on a resonance they didn't have in 1997.

Conservative blogger and activist Pamela Geller was by then writing regularly about the threat posed by Islamic infiltration in the United States, and, in particular, the treatment of women in Muslim countries. Geller rose to prominence among conservatives for her willingness to speak her mind and ability to build a community around her arguments. She exemplified the use of the Internet to share information — correct or not — about Muslim activity in the United States, praising the democratizing aspect of blogs in 2004. Geller wasn't the only blogger to talk about Islam and sharia, but she was one of the earliest.

Television personality Glenn Beck took up the mantle while he was still at CNN in 2006 and 2007. He found himself regularly astonished by a variety of stories about Muslims in the United States and internationally. Here, he discusses an incident in which imams were taken off of a plane — and in which Minneapolis cab drivers refused to drive people transporting alcohol from the airport.

There's a lot of overlap here with the debate over political correctness, it's worth noting. A Beck transcript from February 2007:

Political correctness is going to lead us all, Muslim and non-Muslim, to a place where we're down on our knees and somebody is standing behind us with a machete. We need to wake up and have a frank, honest, non-hate-filled discussion about the dangers of radicalized Islam.

Later, he says that a town in Canada publicized laws barring stoning and burning people alive for new immigrants. Why? "[T]he majority of Muslims and non-Muslims, they already" understand those things, he said. "But immigrants coming from places like Pakistan, where sharia law does exist, may not."

When Beck moved to Fox News and then, later, when he started his own network, he continued to focus on Islam and the Muslim Brotherhood, hosting the Center for Security Policy's Gaffney and helping to publicize his attacks on Norquist.

In 2008, a number of events converged to add fuel to the anti-sharia effort. In Britain, the archbishop of Canterbury expressed support for Muslims in the United Kingdom to adhere to sharia law, prompting widespread backlash. In the United States, incidents in which Muslims were allowed special diets in prison or wanted to build mosques were lumped into the idea of sharia creeping across the landscape — and a blog, "Creeping Sharia," which still publishes, was there to document it. In most cases, as is still the case, the issues at hand had nothing to do with sharia at all.

But the term was used in the same way that Rosenthal suggested in 1997 — to mean "Islamization." Or, often, "Islam-related."

(Above: A news story from November 2008.)

The other thing that happened in 2008, of course, was the Democratic Party nomination and election of Barack Obama as president. As recently as last year, President Obama was believed to secretly be Muslim by 29 percent of the country, including 44 percent of Republicans. After taking office, rumors about Obama and his Cabinet and the Muslim Brotherhood were rampant. Snopes kept busy.

"For critics of Islam, 'sharia' becomes shorthand for extremism," The Washington Post wrote in 2010. At that point, the political topic of the moment was the so-called Ground Zero mosque, a proposed Muslim community center a few blocks from the site of the 9/11 attacks. There was a huge public outcry, at the center of which could be found Pamela Geller. The focus of that Post article was that "sharia" doesn't necessarily mean anything hard and fast — or, at least, there's not universal agreement on what the components of sharia might be. The metaphorical, pejorative use of the term was much less nuanced than the term itself.

The fight over the mosque came a month after Gingrich's speech demanding a federal law banning the use of sharia and at about the same time as an incident in New Jersey gained notoriety. In that case, a judge denied a woman a restraining order against her husband because the husband was following the traditions of his faith when he forced himself upon her. That incident provided fuel to advocates of state measures banning the use of sharia in court decisions, like the constitutional amendment that passed in Oklahoma that November. (It was ruled unconstitutional in 2013.)

At that point, the idea was in the political bloodstream. What's changed since then is the extent to which theories once relegated to the fringes of popular thought have expanded — a shift encapsulated in a quote from Rep. Devin Nunes (R-Calif.), reported in the New Yorker.

“I used to spend ninety per cent of my constituent response time on people who call, e-mail, or send a letter, such as, ‘I really like this bill, H.R. 123,’ and they really believe in it because they heard about it through one of the groups that they belong to, but their view was based on actual legislation,” Nunes said. “Ten per cent were about ‘Chemtrails from airplanes are poisoning me’ to every other conspiracy theory that’s out there. And that has essentially flipped on its head.”

The two-decade-old threat of sharia isn't at the level of chemtrails in terms of conspiracy theories. But the exasperation one can read in Marco Rubio's response this week suggests that it's a concern he's been presented with before and is tired of answering.