If that turned out to be the case, if Perlstein ended up citing the worst comments on this thread to make a point about conservatives, then Perlstein would officially be a first class, dishonest jerk. It would be a proven fact at that point.
I doubt he'd do that to himself. It wouldn't surprise me, though, if he considers this part of his research -- field work, like a safari.
Or he may have just wanted to debate. My guess is that his motivation was mostly "wanted to debate" with a bit of "wanted to study conservatives" mixed in.
At a guess, I'd say it's more like background information. we'll become anomymous examples to support his broadbrush conclusions of conservatives in general.