The question on the poll was which party the person considered themselves affiliated with, but not who they vote for. As other commenters noted, self-declared i

The question on the poll was which party the person considered themselves affiliated with, but not who they vote for. As other commenters noted, self-declared independents typically always vote for one party. If you look at the earlier questions in the article, it accounts for this by placing these "independent" voters into either the Democratic or Republican buckets.