The "great replacement theory" can be traced back at least to Theodore G. Bilbo (D-MS), the brazenly racist U.S. Senator who held office from 1935 to 1947. Bilbo, an antisemite who acknowledged being a member of the Ku Klux Klan during an appearance on "Meet the Press," warned that at "the present rate of interbreeding and miscegenation and intermarriage between the [n-words] and the Whites… there’ll be no Whites, there’ll be no Blacks in this country. We’ll all be yellow [or brown]."

In 1947, Bilbo published a book Separation or Mongrelization: Take Your Choice. In the book, Bilbo argued that "great civilizations of the ages have been produce[d] by the Caucasian race" and the "mongrel not only lacks the ability to create a civilization, but he cannot maintain a culture that he finds around him." He asserted that the nation must choose between a "White America and a mongrel America." 

75 years ago, Bilbo's arguments were seen as extreme. The Saturday Evening Post, an influential conservative publication, called him "America’s Worst Demagogue." In 1946, Senator Robert Taft (R-OH) described Bilbo as "a disgrace to the Senate." There were several efforts to remove him from office prior to his death from cancer in August 1947. 

Bilbo's beliefs, however, were refreshed and repopularized by The Camp of the Saints, the 1973 novel by French author Jean Raspail. The novel is "an apocalyptic tale that attempts to depict the destruction of white, Western society at the hands of mass immigration from the Global South." The book gained popularity "among American white supremacist and anti-immigrant groups in the 1980s and 1990s." 

In 2012, Renaud Camus, a French white nationalist and conspiracy theorist who was influenced by Raspail, wrote The Great Replacement. Camus argued white Europeans "are being reverse colonized by Black and Brown immigrants, who are flooding the Continent in what amounts to an extinction-level event."

The philosophical underpinnings of European white nationalism became increasingly popular among American racists. The white supremacists who gathered in Charlottesville in 2017 chanted "you will not replace us" and "Jews will not replace us." Even though that gathering resulted in deadly violence, the racist conspiracy theory only became more popular. 

It was embraced first by fringe members of Congress like former Representative Steve King (R-IA), who tweeted "[w]e can’t restore our civilization with somebody else’s babies" in 2017. But it was mainstreamed and popularized by Fox News' Tucker Carlson, the nation's most-watched political pundit. In 2021, despite heavy criticism for promoting racist conspiracy theories, Carlson described the great replacement theory as "true" and "what’s happening, actually."  

A December poll found that "about 1 in 3 U.S. adults believes an effort is underway to replace U.S.-born Americans with immigrants." 

On Saturday, 18-year-old Payton Gendron allegedly drove more than 200 miles to a predominantly black neighborhood in Buffalo and, dressed in tactical gear, opened fire at Tops Friendly Market. 13 people were shot and 10 died. Gendron, who has been charged with murder in connection with the shooting, reportedly left behind a 180-page manifesto that "repeatedly cited" the great replacement theory. 

The role of Tucker Carlson in mainstreaming the great replacement theory is well-documented. But the mass shooting in Buffalo raises serious questions about many prominent Republican officials and right-wing advocates who have adopted the great replacement theory in recent years, even as the racist conspiracy was cited as motivation by previous mass shooters in Pittsburgh and El Paso. 

Senator Ron Johnson (R-WI)

Johnson promoted the ideas undergirding the great replacement theory during an April 15, 2022 appearance on Fox Business:

This administration wants complete open borders. And you have to ask yourself, why? Is it [that] really they want to remake the demographics of America to ensure that they stay in power forever?

Senate candidate J.D. Vance

Vance, who recently won the Republican nomination for a U.S. Senate seat in Ohio, referenced concepts associated with the great replacement theory in an April 2022 townhall. He claimed Democrats were plotting to let in 15 million additional immigrants because they were confident that 70% would vote Democratic. 

So you’re talking about a shift in the democratic makeup of this country that would mean we never win, meaning Republicans would never win a national election in this country ever again.

Vance made a similar claim in a campaign advertisement. The ad claims that Biden was deliberately keeping the border "open" to keep "more Democrat voters pouring into this country." In the ad Vance, echoing Carlson, insists he is not "racist" for telling "the truth."

Senate candidate Blake Masters

Masters, a Republican campaigning for the Senate in Arizona, has advanced variants of the great replacement theory on multiple podcasts and videos. He tweeted the claim on Saturday, shortly after the shooting in Buffalo:

Blake Masters @bgmasters

The Democrats want open borders so they can bring in and amnesty **tens of millions** of illegal aliens — that’s their electoral strategy. Not on my watch.

May 14th 2022

689 Retweets2,994 Likes

Congresswoman Elise Stefanik (R-NY)

Stefanik, a member of the Republican House leadership, ran a Facebook ad with a variation of the great replacement theory. It claimed that Joe Biden, Kamala Harris, and Nancy Pelosi were plotting to "flood our voter roles [sic] with 11 MILLION NEW VOTERS by giving illegal immigrants amnesty." 

The Albany Times-Union, Stefanik's hometown paper, said the "despicable" 

ads "repackaged" the great replacement theory.

Congressman Scott Perry (R-PA)

Perry promoted the great replacement theory during a House Foreign Affairs subcommittee hearing on immigration from Central America in April 2021:

For many Americans, what seems to be happening or what they believe right now is happening is, what appears to them is we’re replacing national-born Americans, native-born Americans to permanently transform the landscape of this very nation.

Congressman Matt Gaetz (R-FL)

Gaetz supported Carlson on the great replacement theory and said the Anti-Defamation League was "racist" for calling for Carlson's ouster:

Matt Gaetz @mattgaetz

.@TuckerCarlson is CORRECT about Replacement Theory as he explains what is happening to America. The ADL is a racist organization. Fresh calls for Fox News to fire Tucker Carlson over ‘replacement theory’Host dismisses Anti-Defamation League after organization urges network to drop himtheguardian.com

September 25th 2021

555 Retweets1,876 Likes

Texas Lt. Governor Dan Patrick (R)

In a September 2021 appearance on Fox News, Patrick said Democrats were "trying to take over our country without firing a shot" by inviting millions of immigrants into the country. Patrick said each of those immigrants would have "two or three children" who will support Democrats to thank "Biden for bringing them here." 

Laura, when I say a revolution has begun, they are allowing this year, probably 2 million, that's who we apprehended - maybe another million into this country. At least in 18 years, even if they all don't become citizens before they can vote - in 18 years, if every one of them has two or three children, you're talking about millions and millions and millions of new voters. And they will thank the Democrats and Biden for bringing them here. Who do you think they're going to vote for?

So this is trying to take over our country without firing a shot.

Fox News' Laura Ingraham

In October 2018, Ingraham warned Fox News viewers that Democrats "want to replace you":

Of this my friends you can be sure: Your views on immigration will have zero impact and zero influence on a House dominated by Democrats who want to replace you, the American voters, with newly amnestied citizens and an ever increasing number of chain migrants

Fox News' Jeanine Pirro

In October 2019, Pirro said that Democrats were involved in "a plot to remake America—to replace American citizens with illegals who will vote for the Democrats."

Jason Campbell @JasonSCampbell

Fox's Jeanine Pirro: "It is a plot to remake America. To replace American citizens with illegals"

August 29th 2019

59 Retweets189 Likes

Daily Wire host Matt Walsh

Matt Walsh, who hosts a podcast on the Daily Wire, one of the most popular right-wing websites, promoted the great replacement theory on August 13, 2021. Walsh acknowledged that many people believes the great replacement is racist but, like Carlson, argued that it is a fact:

Now, we are told that if you speculate that the powers that be in this culture want to replace white people, we're told this is the great replacement theory and it is a white supremacist conspiracy theory and it's, pretty much, the worse thing you can ever say… I'm just trying to work through this in my head here, help me out – so we're bringing in a flood of immigrants across the southern border, non-white. We're putting policies in place with the express purpose of having fewer white people in universities and positions of power. And we're celebrating the reduction in the white population. I mean, it sounds like you want to replace white people.

Trump advisor and political operative Steve Bannon

Steve Bannon, the former top aide to President Trump who now hosts a podcast popular with Republican candidates, was at the vanguard of popularizing the great replacement theory with MAGA Republicans. Bannon repeatedly referenced The Camp of the Saints as an explanation for immigration in Europe and elsewhere. "It’s not a migration,” Bannon said in January 2016, “It’s really an invasion. I call it the Camp of the Saints.” 

A few months later, in a June 2016 interview with then-Senator Jeff Sessions (R-AL), Bannon described a "war" against liberals in the United States who were attempting to change the nature of the country through immigration. "Do you believe the elites in this country have the backbone, have the belief in the underlying principles of the Judeo-Christian West to actually win this war?" Bannon asked. At the time, Bannon was editor of Breitbart, a far-right media outlet. A BuzzFeed exposé found that, in the runup to the 2016 election, Breitbart collaborated with white nationalists. 

In the White House, Bannon was the driving force behind Trump's ban on immigration from several Muslim countries. 

Trump advisor Stephen Miller

During the 2016 campaign, Stephen Miller, then an aide to Sessions, was in close communication with editorial staff at Breitbart. In one email, Miller encourages former Breitbart  editors Katie McHugh and Julia Hahn to incorporate The Camp of Saints in their immigration coverage. 

Miller, Sept. 6, 2015, 3:41 p.m. ET: “[Y]ou see the Pope saying west must, in effect, get rid of borders. Someone should point out the parallels to Camp of the Saints.”

A couple of weeks later, Hahn did just that:

In the emails, Miller also "pushed racist immigration stories and obsessed over the loss of Confederate symbols after Dylann Roof’s murderous rampage."

After Trump became president, Miller joined the White House, where he championed hardline immigration positions. Miller currently runs America First Legal, which accused the Biden administration of "aiding, abetting, and accelerating the worst invasion of America’s southern border in history."

President Donald Trump

Trump won the presidency fear-mongering about immigrants. In a July 2017 speech in Poland, Trump deployed the language of the great replacement theory. He described immigration as an issue of "survival" for "the West." Migrants were part of a plot to "subvert and destroy" our "civilization."

The fundamental question of our time is whether the West has the will to survive. Do we have the confidence in our values to defend them at any cost? Do we have enough respect for our citizens to protect our borders? Do we have the desire and the courage to preserve our civilization in the face of those who would subvert and destroy it?

The speech was reportedly written by Miller.