They would have won because the communists would murder anyone who voted against them
Korean communists had no reason to kill opposing voters between 1945 and 1950 because they were in the majority. US forces, on the other hand, resorted to killing their political opponents frequently and without any regard for"democracy" or human rights:
Autumn Uprising of 1946 - Wikipedia
"The
10.1 Daegu Uprising of 1946 (
hangul: 대구 10·1 사건;
hanja: 大邱 10·1 事件) in
Korea was a peasant uprising throughout the southern provinces of Korea against the policies of the
United States Army Military Government in Korea headed by
General John R. Hodge and in favor of restoration of power to the people's committees that made up the
People's Republic of Korea..."
"According to the conditions the United States Military Government responded in different ways, including mobilizing
strikebreakers, the police, right-wing youth groups, sending in U.S. troops and tanks, and declaring
martial law, and succeeded in putting down the uprising.
"The uprising resulted in killing of 38 policemen, 163 civil workers, and 73 civilians.
[2]
"Some analysts say that the uprising, which was in part a reaction to the October elections for the South Korean Interim Legislative Assembly, organized by the United States Military Government, is a better indicator of public opinion than the election itself."