I've been downvoted below zero plenty of times -- sometimes when I am attempting to present a non-standard potentially provocative opinion -- but often not. I've also had comments that started off w/ a few upvotes and then went south to -4, and others that started off w/ a few downvotes and went up (this is less frequent).

I think part of the problem is you get penalized pretty quickly w/ the shading differences, and people are happy to knock you down. Believe it or not, the post you are responding to go at least one downvote before the upvotes boosted it back to normal text color.

As for your tactic for "post[ing] your truth" this doesn't work so much if it does get downvoted, since it fairly quickly becomes near invisible.