If there was a place to report instances of overzealous downvoting, maybe the admins could initiate some action. Is there such a place?
Yes, there is such a place; this meta site. But before we are overwhelmed by disgruntled questioners, I have to define 'overzealous'. If one person downvoted a large number of your questions in one day, it's a fair bet that it is unrelated to the quality of your posts; this is 'abusive downvoting', which is banned, and should be reported here if the automatic systems don't catch it. But if a large number of people downvote one of your questions (remember that they are each sacrificing a point of rep to improve the site, as they see it), that is probably a sign that the question doesn't belong here. This doesn't mean "You're stupid"; it means that a site to do with English is in constant danger of being diluted to the point of uselessness, so we have strict guidelines about what questions are allowed here. You haven't put a link to your question, so I'm guessing; but the minimum expected is that the questioner should have: checked the FAQ to see whether it's on-topic: consulted authorities (dictionaries, grammars, Google for usage), and explained how the answers there are insufficient: and put as much effort into framing the question clearly as he expects from an answerer. If other users of the site think you didn't do this, you will be downvoted, and there is no comeback against commmunity moderation; either improve your posts (improve here meaning make more suitable to EL&U rules), or find another site that suits you better.