This is the 4914th most frequent Korean word.
국민투표를
"국민투표를" means "referendum" or "national vote."
In this sentence, "국민투표를" indicates the tool or method being used for consultation of public opinion.
국민투표를 통해 국민의 의견을 직접 반영합니다.
Through the referendum, the opinions of the people are directly reflected.
Here, "국민투표를" describes the object of the announcement.
대통령은 국민투표를 공식적으로 선언했습니다.
The president officially announced the referendum.
In this context, "국민투표를" refers to the action of possibly employing a referendum as a decision-making process.