The New York Times should've given readers a heads-up after making alterations to a story about Bernie Sanders' legislative record that substantially changed the tenor of the article, Public Editor Margaret Sullivan wrote Thursday.

Sullivan was writing in response to a pair of stories — one written by Rolling Stone's Matt Taibbi and one penned by The Washington Post's Erik Wemple — which noted the newspaper appended two paragraphs that qualified the legislative achievement Sanders was able to accomplish in the Senate. Taibbi accused the Times of "sandbagging" Sanders and Wemple wondered publicly why the paper "changed its mind" about the Democratic candidate.

In remarks to Sullivan, Times editors Matt Purdy and Michael Tackett said that the changes were about "nuance and depth" made at "the pace of the Web" and, as such, don't require some kind of editor's note. Not so, Sullivan says:

The changes to this story were so substantive that a reader who saw the piece when it first went up might come away with a very different sense of Mr. Sanders’s legislative accomplishments than one who saw it hours later. (The Sanders campaign shared the initial story on social media; it’s hard to imagine it would have done that if the edited version had appeared first.)

Given the level of revision, transparency with the readers required that they be given some kind of heads-up, and even an explanation.