During the 2016 election, Trump said during a Fox News interview that Ted Cruz's father, Rafael Cruz, was with Lee Harvey Oswald before Kennedy was shot.
"What was he doing with Lee Harvey Oswald shortly before the death, before the shooting? It's horrible."
The theory was fueled in part by the National Enquirer, which published a photo that it claims shows Rafael Cruz with Oswald handing out pro-Fidel Castro pamphlets.
Ted Cruz has denied the allegations.
"Yes, my dad killed JFK, he is secretly Elvis and Jimmy Hoffa is buried in his backyard," he joked during a 2016 interview.