Perhaps this is because the United States allows dual citizenship, so emigrants there have more political freedom and security. Or perhaps this is because the people who responded to the survey in the first place are likely to be those most concerned about politics in Taiwan.
或許這是因為美國默許雙重國籍，移民在當地擁有較高的政治自由與安全感；或許基本上願意回答問卷的人，就是對國內政治關注程度較高的。