By Nathan Layne, Nandita Bose and Joseph AxGLENDALE, Arizona (Reuters) -A memorial service for Charlie Kirk on Sunday is expected to draw a massive crowd at a football stadium in Arizona, where President Donald Trump, Vice President JD Vance and other prominent MAGA allies will pay tribute to the slain conservative activist. Security will be extremely tight, given Trump’s attendance as well as the ongoing political turmoil in the aftermath of Kirk’s death. Kirk, 31, was assassinated by a single bullet on September 10 during a campus event in Utah. The roster of speakers at Sunday’s service, titled “Building a Legacy: Remembering Charlie Kirk,” demonstrates Kirk’s influence as the leader of the country’s biggest conservative youth organization. Mitchell said it was Kirk who inspired him to speak out as a young conservative.