Why would the opposite necessarily be "on the fence"? This is both a false dichotomy and false analogy. The vast majority of users aren't "on the fence", meaning the more likely person on the other end of the argument is avidly anti-racist.
What if said "on-the-fence" individual visits stormfront? Who's to argue against it there? No one.
> nothing is stopping you from searching them out to do so.
Except there is. Racist forums are walled gardens. They're safe-spaces for white supremacists. They don't invite dissent.
> Daryl Davis went I to people's homes and met them in person to befriend and sometimes "convert" them. It wasn't accidental cross pollination. He explicitly reached out.
In person, correct. If this is to be analogous to the real world, other users on a popular social media platform like reddit are your neighbors. And obscure radical forums are like impenetrable cult compounds. You can reach them out online, when in plain view, but this isn't as easily accomplished in every medium.
More importantly, you're framing racism as an infectious view that could plague just about any innocent bystander. It's more fragile than that, in terms of logical merit (there is none). I think the exposure makes it more vulnerable.