A white supremacist mass shooter in Buffalo killed 10 people and wounded another three — 11 of whom were Black — and left behind a manifesto that clearly indicated he had been inspired to commit his crime by the "Great Replacement Theory”.
Mr Carlson, who helms the most-watched political opinion programme in the country, has frequently pushed the Great Replacement Theory during his shows. A compilation of him touting the ideas recently went viral on social media.
Adherents to the Great Replacement Theory believe that there is a concentrated effort by liberals to replace white Americans as the dominant cultural force in the country by importing people of colour and immigrants, who Mr Carlson says are "obedient" and will vote for Democrats.
"So I know that the left and all the little gatekeepers on Twitter become literally hysterical if you use the term 'replacement', if you suggest the Democratic Party is trying to replace the current electorate, the voters now casting ballots, with new people, more obedient voters from the third world," Mr Carlson said. "But they become hysterical because that's that's what's happening actually. Let's just say it. That's true."
When asked for comment, a spokesperson for Fox News pointedThe Independent to Mr Carlson’s on air remarks denouncing political violence of any kind.
Despite the fact that immigrants and people of colour do not vote in monolithic blocks, some conservatives have accepted the conspiracy theory as true, and it has fuelled some of the worst modern mass shootings.
Both the 2019 mosque shooting in Christchurch, New Zealand, and a 2018 shooting at the Tree of Life Synagogue in Pittsburgh were motivated in part by complaints that white people were being replaced.
Mr Carlson said that "demographic change is key to the Democratic party's political ambitions" in another segment.
"In other words you're being replaced and there's nothing you can do about it so shut up!" he said before letting out a maniacal laugh.
In another episode he was less veiled in this feelings on the issue, claiming that "our country is being invaded by the rest of the world”.
"I'm going to state unequivocally the country is being stolen from American citizens as we watch." he said in another segment.
Last September he even used the name of the theory, saying the "policy is called the 'Great Replacement,'" which he said was the "replacement of legacy Americans with more obedient people from faraway countries."
By "legacy Americans," he means white.
Those are only a sample of the times Mr Carlson has pushed the ideology; a New York Times report found 400 instances of the pundit suggesting that Democrats are trying to force a demographic change to improve their election chances.