The web developer at my company is against having down-voting on comments after we spent days writing the code because people are using it to express disagreement over statements, and thinks that'll lead to users leaving the site who don't use the product.
I completely disagree.
The argument is that if a liberal posts a comment on a poll on a day when a lot of conservatives use the site, and the conservatives all down-vote his comment, that he might be turned off and not come back.
I find this to be incredulous. If the liberal were to create a poll that was "Obama vs. Ron Paul" and a lot of conservatives were on the site at the time and beat Obama by a few thousand votes (a likely scenario) then he's probably more likely to be turned off than if someone down-voted his comment because they disagreed.
I am really interested in getting everyone else's opinion on the subject of down-voting comments.