All scores obtained using Vader sentinment analyzer
As expected, the sentiment scores for citations in news texts are not very biased towards positive or negative. Sentiment score averages are pretty close to zero. There are some modest differences, American news sources being very close to zero point and rest of the sources, being a bit on the positive side.
Plotting all citation sentiments indicate that
1) Most citations are neutral (0 or very close),
2) Distribution is fairly even between negative and positive and
3) The New York Times seems to have citations with milder opinions than others (caveat: very few articles)
For opinion articles, the sentiment scores are more pronounced, maybe even surprisingly pronounces. Note that here the sentiment analysis is applied to the full text of the opinion article.
When analyzed by paragraph, the sentiment scores vary more, of course.