I have often observed this pattern and now I have one example where it is rather clear.
I often have the impression that users with a high reputation tend to get upvotes, even in cases where the answer is wrong, or at least not helpful. I remember a post where a high rep user got a lot of upvotes for an answer that was totally irrelevant to the actual question, even though it was technically correct.
I was looking at this question: Writing line by line to file with c, which I answered. From the question it was not that obvious that the user intentionally creates many files so the answer was to create his files outside. A high rep user posted a similar answer at the same time. Following the comments and reading the question more carefully, reveals that the answer is wrong, but he still got an upvote for it. The upvote came long after the comments were already posted, clarifying that the answer is wrong.
So I wonder how can voters be taught to actually look at the answer provided in relation to what was asked. Sometimes I have the impression that longer answers look more "professional" and thus get the upvotes and such answers tend to come from high rep users more often.
Here (Structure instance restriction in C or C++) is another such a case IMO, as the answer is not really an answer and neither does it adress the question.
So I wonder how can voters be taught to actually look at the answer provided in relation to what was asked.why, if the OP's question is the wrong approach in the first place? While there surely is some bias towards high-rep answerers, this not a good example.