People always forget about the lurkers. Most people with less-informed, more impressionable views on a given topic aren’t posting and debating, they’re reading and learning (despite the unfortunate exceptions). Seeing some wacko extremist nonsense or voter suppression tactic go unchallenged by a more reasonable argument may be enough to sway a not-yet-fanatic in the wrong direction.
We already know what he looks like in a cowboy hat, and that ain’t it.