I have got them before a couple of times. A long time ago and it's pretty rare. People newly from reddit! A couple of times I got one because I had made a snap that was a dupe or similar to someone else's and they got a bit stroppy. I figure that just happens sometimes.
You have to give a reason for downvoting. This one said "Misleading / clickbaity / Sensationalized". Maybe. US politics is so riven.
At least when you get a downvote for a re-post it doesn't mess with your reputation score.