Sorry to shatter your illusions, but unlike the leftist NPCs I mentioned I don't care what others think. I was never afraid to speak up during my time at an Ivy League university where the most common political posters were for the "world socialism" movement. In more than a decade on Reddit (or here) I have
never once complained about being downvoted, and the first time I mentioned the concept of being up/downvoted at all was many years into my tenure there in response to some question/discussion not dissimilar to this.
The next time you are about to post something online, or say something to friends, or patronize a business, do you first ask yourself "What would it do to my public image if other people I knew saw me doing this?", and let that affect your behavior? Not me.
PS - I can also say that I have never up/downvoted a comment anywhere simply because I disagreed with it. I have upvoted many comments critical of me, or something I believe in/agree with, because of their eloquence or wit. I downvote very, very, very few comments, and only because they are completely useless (say, off topic), or ridiculously foul-mouthed in an inappropriate context (by the same token, I have upvoted such if funny enough). Even if few others seemingly believe in the original rationale for up/downvoting, I still do.