Ok now I've looked, if one was able to see individual karma for each user who submitting a reply to the submission, the answer is sometimes but on more controversial topics the answer would be no as per
< Downvoting Comments
All comments start with a score of 1 point (but in order to prevent bandwagoning, the comment score is not visible to users other than the author). After users reach 501 Karma, they gain the ability to downvote another comment. Downvoted comments (i.e. with a score < 1) reduce their placement on the comment thread and will appear desaturated to other users deemphasize them. There is no upper limit on the score of a comment, but the minimum score is -4 points. Additional downvotes after that still subtract points from the user's Karma, but the comment won't go below -4. You cannot downvote comments which are direct replies to your own comment, and you cannot downvote 24 hours after the original comment was made.
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I even managed to work out something curious for myself - Even though the comment's recorded or listed karma can't dip below -4, but as I found in particular a user's karma can still take a significant hit if they've responded and annoyed a certain clique of people draw to the topic subject.