Joe Biden has said "hate will not prevail" as he attacked the “hateful and perverse ideology” behind the "domestic terrorism" of the Buffalo massacre in which a gunman killed 10 people in a racially-motivated shooting in New York.
The US president said his country must "reject the lie" of the racist "replacement theory" - the false notion that white Americans are being deliberately replaced through non- white immigration.
"In America, evil will not win. I promise you. Hate will not prevail. White supremacy will not have the last word," Mr Biden told a news conference on Tuesday. "What happened here is simple and straightforward terrorism, domestic terrorism, violence inflicted in the service of hate, and a vicious thirst for power. "The hate that through the media, and politics, the internet, has radicalised angry, alienated and lost and isolated individuals into falsely believing that they will be replaced by the other."
'There's nothing we can do that’s going to take away the hurt,' former Buffalo Fire Commissioner Garnell Whitfield Jr said of his late mother
His remarks came hours after he paid respects alongside First Lady Jill Biden at a makeshift memorial to the 10 people killed in the white supremacist attack in Buffalo.
The couple laid a bouquet of white flowers at the memorial outside the Tops supermarket, where on Saturday a man armed with an assault rifle targeted black people in the deadliest racist attack in the US since Mr Biden took office.
The Bidens were meeting privately with families of the victims, first responders and local officials before the president spoke publicly about the need for stricter gun laws and embracing the nation’s diversity.
It’s a message that Mr Biden has delivered several times since he became the first president to specifically address white supremacy in an inaugural speech, calling it “domestic terrorism that we must confront".
However, such beliefs remain an entrenched threat at a time when his administration has been focused on addressing the pandemic, inflation and the war in Ukraine.
Three more people were wounded in Saturday’s attack and nearly all the victims were black, including all of those who died.
On Monday, Mr Biden paid particular tribute to one of the victims, retired police officer Aaron Salter, who was working as a security guard at the store.
He said Mr Salter “gave his life trying to save others” by opening fire at the gunman, only to be killed himself.
The shooter's hateful writings echoed those of the white supremacists who marched with torches in 2017 in Charlottesville, Virginia, in a scene that Mr Biden said inspired him to run against Donald Trump in 2020.
Proposals for new gun restrictions have routinely been blocked by Republicans, and racist rhetoric espoused on the fringes of the nation's politics has only grown louder.
Payton Gendron, 18, was arrested at the supermarket and charged with murder and has pleaded not guilty.
Before the shooting, Gendron is reported to have posted online a screed overflowing with racism and antisemitism.
Its writer described himself as a supporter of Dylann Roof, who killed nine Black parishioners at a church in Charleston, South Carolina, in 2015, and Brenton Tarrant, who targeted mosques in New Zealand in 2019.
What is the 'great replacement theory'?
Investigators are looking at Gendron's connection to what's known as the “great replacement" theory, which baselessly claims white people are being intentionally overrun by other races through immigration or higher birth rates.
The claims are often interwoven with anti-Semitism, with Jews identified as the culprits. During the 2017 “Unite the Right” march in Charlottesville, white supremacists chanted “Jews will not replace us."
"Many of those dark voices still exist today,” White House press secretary Karine Jean-Pierre said on Monday.
“And the president is determined as he was back then... to make sure we fight back against those forces of hate and evil and violence.”
In the years since Charlottesville, replacement theory has moved from the online fringe to mainstream right-wing politics.
A third of adults in the US believe there is “a group of people in this country who are trying to replace native-born Americans with immigrants who agree with their political views,” according to a poll conducted in December by The Associated Press and the NORC Centre for Public Affairs Research.
Tucker Carlson, the prominent Fox News host, accuses Democrats of orchestrating mass migration to consolidate their power.
“The country is being stolen from American citizens," he said on August 23, 2021. He repeated the same theme a month later, saying that “this policy is called the great replacement, the replacement of legacy Americans with more obedient people from faraway countries".
Mr Carlson's show routinely receives the highest ratings in cable news, and he responded to the furore on Monday night by accusing liberals of trying to silence their opponents.
“So because a mentally ill teenager murdered strangers, you cannot be allowed to express your political beliefs out loud,” he said.
His commentary reflects how this conspiratorial view of immigration has spread through the Republican Party ahead of this year's midterm elections, which will determine control of Congress.