I tried to do this on a few different sites, but in my experience, there simply aren't enough good-faith actors. The dirtbag left[0] reigns over the nice fellows in leftist circles on Reddit, Twitter, and Facebook. They don't want to engage capitalists in debate... they don't even want anyone in their own ranks playing devil's advocate. They want to call you a chud and take a screenshot of it.
[0]: https://en.wikipedia.org/wiki/Dirtbag_left