Kou Voravong
The political crisis caused by his assassination, barely two months after the Geneva Agreements which prepared to restore peace in Indochina, contributed to bring down the current neutralist government (pro-French) which was replaced by a progressive one (pro-American) in extremely tense atmosphere of the Cold War between Russia and the United States. From 1955 indeed, the political history of this small landlocked country fell trapped inexorably in the ideological confrontation between the capitalist United States and the communist Soviet Union, annihilating any hope of national unification.
Death of Edgar Allan Poe
Because Poe was found on the day of an election, it was suggested as early as 1872 that he was the victim of cooping. This was a ballot-box-stuffing scam in which victims were shanghaied, drugged, and used as a pawn to vote for a political party at multiple locations. Cooping had become the standard explanation for Poe's death in most of his biographies for several decades, though his status in Baltimore may have made him too recognizable for this scam to have worked. More recently, analysis suggesting that Poe's death resulted from rabies has been presented.