There's nothing to discuss? Clearly this is someone who doesn't want to communicate, and politely asking them to go elsewhere is appropriate. ¯\_(ツ)_/¯
In what way do they “clearly” not want to communicate? Sounds more like your feelings are hurt that someone is speaking against your political tribe.
Perhaps you replied to the wrong comment? The comment you're replying too makes a certain case with a lot of supporting evidence.
Remember that the downvote is not a disagree button.