White gunman, suspected of killing 10 black people, had also posted online about the so-called Great Replacement theory
This week, United States President Joe Biden called the "Great Replacement" conspiracy theory a "source of violent hatred."
Right-wing politicians and media celebrities have echoed the theory, including Fox News presenter Tucker Carlson and Republican politicians.
Analysts think the theory is growing more popular due to the mass shootings in the US, Canada, and New Zealand.
A recent example of how the theory incites violence is the Buffalo attack. The white gunman, suspected of killing 10 black people in the attack, had also posted online about the so-called "great replacement" theory.
"I call on all Americans to reject the lie and I condemn those who spread the lie for power, political gain, and profit," President Biden had said on Tuesday in Buffalo, New York, following the attack.
The "great replacement" theory was also repeatedly mentioned in a manifesto linked to the Buffalo shooter, who officials have said purposefully targeted the neighbourhood in a racist, an anti-Black hate crime.
The "Great Replacement" theory, according to the National Immigration Forum," frequently uses a martial and aggressive vocabulary of a migrant "invasion" that must be halted before it "conquers white America."
The white supremacist conspiracy incorrectly claims that white people are being replaced and losing their social status as a result of a plot to increase non-white immigration and other reasons, such as non-white birth rates.
While analysts have emphasised that the conspiracy's worldview is not new or exclusive to the United States, they have warned that in the aftermath of the Buffalo shootings, the "Great Replacement" notion has taken the centre stage in the common discourse.
Speaking at a show and highlighting the "double standards" of western white media, notable journalist Mehdi Hasan raised a question on the theory.
He said that "if you and I (brown Muslim men) on TV were echoing and saying the racist and conspiracies stuff that Muslim brown terrorists were saying, we would be rightly finished as public figures."
"How is it that conservative cable hosts can basically say the same stuff that white supremacist terrorists are saying?" He questioned.
Watch here Mehdi Hassan's show here:
Al-Jazeera reported that anAssociated Press-NORC Centre for Public Affairs Research poll showed that almost 32% of Americans believed “that a group of people is trying to replace native-born Americans with immigrants for electoral gains."