In current moderator elections such as the Math election, I can't upvote comments. I've also been told by higher rep users and moderators that they can't upvote comments either. I know this was possible in the 2014 Stack Overflow Election, as you can see by the large number of upvotes on almost all of the comments.
Was the ability to upvote comments underneath a nomination removed for a reason? Or is this just a bug?