I'll defer to the answer from someone who knows better than me what can and can't be done within the software and by digging deeper. That said, since the votes cast are visible to the user who cast them, of course the data is there; therefore, if there's suspicion of poor voting behavior, the exact votes cast can be analyzed in more depth.
However, I do want to point out that just because a particular user is more inclined to vote a particular way (either up or down) on posts (questions, answers, articles, ...) that are posted by a particular other user, that does not necessarily make even the voting user's behavior inappropriate. It might, but it need not.
For example, there might be something recurring about that user's posts which they disagree with. Such things could be posts that are simply reposted from elsewhere, or posts that are difficult to read due to formatting or even severe language difficulties, or posts that are (or they feel should be) clearly off topic on the community in question, or that a user basically takes a shotgun approach to posting only to abandon the post and not respond to either requests for clarification or suggestions for how a post can be improved.
On the flip side, if a user consistently takes great care with how they word their posts such that they are as clear and focused as possible right from the get-go, responds promptly to feedback, explains their ultimate goal as well as asking a specific question (or, alternatively, makes it clear how their answer actually answers the question that they are responding to), and generally engages with the people who invest of their own time and energy to provide answers for free, then it seems reasonable to assume that, on average and in the eyes of a particular reader, posts by that user are more likely to be worth upvoting.
Neither of those are in any way intended as an exhaustive list of reasons; they are simply some that I can think of off the top of my head that might make someone more inclined to vote one way or the other on a particular user's posts. And notice that neither has much to do with who posted some particular piece of content. Although there can be a correlation, those remain properties of primarily the posts and to a lesser extent of the user's behavior, not of the user as such.
What's problematic is, rather, targeted voting. Which I define as someone voting, either up or down, not based on the quality of a post but rather based on which user posted it. Going through a user's profile is one way this can happen, but that need not be the case. If someone goes to the front page of a community, sees ten posts by user SomeSpecificDisplayname, opens them and votes on them without even reading them, that's targeted voting by my definition even though no user profile page was ever accessed. And while it's the downvotes that tend to get people worked up, such behavior is equally problematic whether that user votes up or down.