I don't see a
redirect to "Gun Control" in the page history. It is currently a redirect to "Right to Keep and Bear Arms", yes; but before that, it was a disambiguation page that had a brief explanation of various meanings, and links to several other, more detailed pages. So if Google captured that, shouldn't it be linking to that disambiguation page?
Even then, one could imagine that the Google could somehow detect that it is not a particularly informative page, and pick the most likely disambiguation link out of it. Logically speaking, that would be first link in the list. But before the page was changed to be a pure redirect, it had the following blurb at the very beginning:
The term "'''Gun rights'''" may refer to:
* The legal concept of the [[right to keep and bear arms]]
* [[Gun control]], the set of laws or policies that regulate the
manufacture, sale, transfer, possession, modification, or use
of firearms by civilians.
...
So, why would the algorithm pick the second link, specifically? And why hasn't it re-indexed the page since?
FWIW, I don't think this is the case of deliberate changing of search results. But I suspect that their algorithm is inadvertently picking up bias from somewhere else, and applying it here.