Huey Long died after being shot by a doctor, who was shot dead by Long's bodyguards. I read that it's possible that the bullets which actually killed Long may have come from the bodyguards' guns--ricocheting off the walls in a confined space. Of course Sirhan wasn't shot dead on the spot.
In Huey Long’s case FDR’s deep cover agents “helped” blame a totally (now) vindicated Jew— a fact of the times. Blame the Jew in the LA “parish”. Meanwhile, it was actually one of Huey’s bodyguards.
Certain knowledgeable folks in LA can tell you, Huey was a threat to FDR’s leftist fascism. Long correctly identified the fedgov dipping into the litle man’s pocket to benefit the big man. The subject of decades of personal life experience for most folks (Southern and Northern) from the Dust Bowl forward.
An excellent book on the anti-semitism of FDR admin(and the Foggy Bottom State Department) is Erik Larson’s “In the Garden of the Beast- An American Family in Pre-WWII Berlin”. FDR’s concern was that of his oligarch buddies (who had to be forced not to do business with Hitler, and even then, continued to do so- See the anti-knock additive Standard Oil sold in the multimillions to the Nazis throughout the entire war, and Henry Ford’s war reparations paid to Ford for the bombed out Ford plant). Such were the globalists then, and now.