 The referendum was widely condemned for being fraudulent . Historian and writer Jessica Chapman said " Even Diệm apologists like Anthony Trawick <unk> and American CIA officer Edward Lansdale concur with the prime minister 's harshest critics on the conclusion that the South Vietnamese government was either incapable of or unwilling to hold a truly free , representative plebiscite " . A CIA report written in 1966 adjudged the poll to be the most heavily manipulated in the first 11 years of South Vietnam 's history . The U.S. government privately concluded that the monopoly Diệm had on the media and the election campaign was a greater factor in the victory than intimidation and the fact that the voting was effectively public . Reinhardt cabled Washington , saying that the " referendum proved [ a ] resounding success for [ the ] Diem government " . He indicated that the poll results were not necessarily a reflection of reality by adding that the result did not show that Diệm had majority support but that he was able to control the country , effectively unchallenged . The U.S. government was heartened by Diệm 's apparent ability to negate communist and other opposition . 
