I would like to have the option to search for down voted questions and answers.
Searching for down voted posts will help to improve posts with low quality and flag/delete unrelated posts and spam.
add a search option similar to
votes:-1 selecting all posts with a negative score.
votes:-2 selecting all posts with a score of -2 or lower.
and so on.
As mentioned here it is not possible to search for down voted questions. This can be done by a workaround but only if the result set is smaller than 5.000 questions.