Video above: Crowds gather to attend Charlie Kirk memorial, hours before doors open.

(NEXSTAR) — Supporters are set to gather Sunday in Arizona to pay tribute to Charlie Kirk, the conservative activist who was assassinated in Utah earlier this month. The free tribute event, hosted by Kirk’s Turning Point USA, is expected to draw tens of thousands of supporters and mourners.

Kirk, 31, was fatally shot while speaking at Utah Valley University in Orem, Utah, on Sept. 10. A 22-year-old Utah resident is now facing charges in his death.

Sunday’s memorial service is set to take place at State Farm Stadium in Glendale, Arizona, just outside of Phoenix, where Turning Point USA is based.

Doors are scheduled to open at 8 a.m. MT (11 a.m. ET) with the program starting at 11 a.m. MT (2 p.m. ET). As of Saturday night, hopeful attendees were already lining up outside the stadium.

A live stream of the service will be carried live in the video player above.

President Donald Trump, Vice President JD Vance, and other prominent members of the Republican Party are expected to be in attendance on Sunday. In addition to Trump and Vance, scheduled speakers include Health and Human Services Secretary Robert F. Kennedy Jr., Defense Secretary Pete Hegseth, Director of National Intelligence Tulsi Gabbard, Donald Trump Jr., right-wing commentator Tucker Carlson, and White House aides Stephen Miller and Sergio Gor.

Slideshow: Supporters pay tribute to Charlie Kirk

Longtime worship leader Chris Tomlin will provide music, along with other big names in contemporary Christian music, including Brandon Lake, Phil Wickham, and husband-and-wife duo Kari Jobe Carnes and Cody Carnes.

Kirk’s widow, who has been named Turning Point’s new leader, also will speak. Erika Kirk pledged in an emotional speech days after his death that “the movement my husband built will not die.”

Attendees, who had to register ahead of time to attend, have been encouraged to wear their “Sunday best – red, white, or blue,” according to Turning Point. The organization also warned of enhanced security measures, including “TSA-level screening.”

On Friday, police arrested an armed man at State Farm Stadium, saying he was “exhibiting suspicious behavior.” The 42-year-old allegedly “falsely claimed to be a member of law enforcement and stated that he was armed,” when approached by the Secret Service. He was then charged with impersonating a law enforcement officer and carrying a weapon into a prohibited place.

However, Andrew Kolvet, an executive producer for “The Charlie Kirk Show,” said Saturday that the man was doing advance security for a guest of the memorial service, The Hill reported.

“We do not believe this person was attempting anything nefarious, however the advance was not done in proper coordination with the TPUSA security team or US Secret Service,” Kolvet wrote.

Kirk’s legacy of conservative political influence

Turning Point, the group Kirk founded to mobilize young Christian conservatives, became a multimillion-dollar operation under his leadership with enormous reach.

The tens of thousands expected to fill the stadium in Glendale for Kirk’s memorial is a testament to the massive influence he accumulated in conservative America.

Kirk was a provocateur who at times made statements that some called racist, misogynistic, anti-immigrant and transphobic. That has drawn backlash from conservatives who view the criticism as cherry-picking a few select moments to insult the legacy they see of an inspirational conservative leader.

Kirk was a MAGA celebrity with a loyal following that turned out to support or argue with him as he traveled the country for the events like the one at Utah Valley University, where he was fatally shot. Kirk grew the organization, in large part, through the force of his personality and debating chops.

Arizona is the adopted home state of Kirk, who grew up outside Chicago and founded Turning Point there before moving the organization to Phoenix. Vance, who has said Kirk’s advocacy was a big reason Trump picked him to serve as vice president, transported Kirk’s casket from Utah to Arizona aboard Air Force Two the day after his death, and he later served as a guest host of Kirk’s podcast.

The Associated Press contributed to this report.