For what it's worth, I always upvote downvoted comments when they are contributing something novel to the thread and/or taking a position which is explained and justified, and of course are civil. Even when I wouldn't have otherwise upvoted them, or when I don't agree with them.

That's just to help get them back to neutral, and avoid their point being grayed out and thus probably more likely skipped over by others. I think everyone should be allowed to put across their point, and we all end up better for seeing those different angles.

I quietly hope that others who agree with this also do the same, thus making the problem you describe a little less pronounced. We all need to play our role in creating the kinds of online communities we want to see.