US President Donald Trump and top officials in his administration will lead tributes to Charlie Kirk at a stadium gathering in Arizona, after the influential conservative activist was fatally shot last week.
Mr Kirk, 31, was shot in the neck on 10 September while speaking at a Utah university as part of his popular public debate series.
Authorities arrested a suspect after a 33-hour manhunt, with prosecutors seeking the death penalty in the case.
The killing of the young conservative leader, founder of the Turning Point USA right-wing youth action campaign, has further deepened acrimonious political divisions in the US.
Authorities say the suspected 22-year-old gunman cited the "hatred" he believed was stoked by Mr Kirk - who was a vitriolic critic of transgender people, Muslims and others.
Mr Kirk used his millions of social media followers, the massive audience of his podcast and appearances at universities to bolster Mr Trump with young voters and fight for a nationalist, Christian-centric political ideology.
Even before the alleged killer was identified or arrested, Mr Trump called Kirk "a martyr for truth and freedom" and blamed the rhetoric of the "radical left."
The US President has lauded Kirk's role in helping him get re-elected in November last year.
In Phoenix, outside Turning Point USA's headquarters, hundreds marched yesterday to lay flowers, American flags, and red, white and blue balloons.
The sidewalk was filled with tributes to Mr Kirk, depicted in photos with the slogan "Faith, Family, Freedom."
"He was an amazing young man, who was taken away from us much too soon," said Patti Peteque, 53.
Crackdown on liberal 'terrorism'
Mr Trump, Vice President JD Vance, Secretary of State Marco Rubio and Defense Secretary Pete Hegseth will all speak at the memorial.
Also speaking will be Director of National Intelligence Tulsi Gabbard, Health Secretary Robert F Kennedy Jr., conservative commentator Tucker Carlson and other prominent Trump administration officials.
Mr Kirk's widow, Erika Kirk, who is taking over the reins of Turning Point USA, will also address the audience at the 63,000-seat State Farm Stadium in Glendale.
In response to the killing, the White House last week declared it would crack down on what it terms "domestic terrorism" by the political left.
Mr Trump said he would designate "Antifa" - a shorthand term for "anti-fascist" used to describe diffuse far-left groups - as "a major terrorist organization," a move he threatened in his first term.
Prominent late-night talk show host Jimmy Kimmel was yanked off the air Wednesday, hours after the government threatened to cancel broadcasting licenses because of comments he made about Mr Kirk's killing.
The moves have sparked alarm among Mr Trump's critics who warn of possible steps to silence dissent of his divisive right-wing White House tenure, marked by a rolling back of social justice policies and an immigration crackdown that has seen widespread complaints of rights abuses.
"All over the world, Amnesty International has worked for decades to expose and document the silencing of dissent through a range of tactics, and we are deeply concerned such efforts are becoming normalised here," said the rights group's Executive Director Paul O'Brien on Friday.
Many on the right-wing in the United States, however, see things differently.
"The left is just getting a taste of their own medicine. Who stood up when we felt censored, when we felt cancelled?" said Ms Peteque, the mourner in Phoenix.
