Mill states it well: "He who knows only his own side of the case knows little of that." If someone can correctly explain a position but continue to disagree with it, that position is less likely to be correct. And if ability to correctly explain a position leads almost automatically to agreement with it, that position is more likely to be correct.
[...] Put me and five random liberal social science Ph.D.s in a chat room. Let liberal readers ask questions for an hour, then vote on who isn't really a liberal. Then put Krugman and five random libertarian social science Ph.D.s in a chat room. Let libertarian readers ask questions for an hour, then vote on who isn't really a libertarian. Simple as that.
My challenge: Nail down the logistics, and I'll happily bet money that I fool more voters than Krugman.
Just like Caplan, I'd like to put my money where my mouth is and play in an ideological Turing Test against a Christian blogger.
UPDATE: Two Christians have contacted me to tell me they're interested. Please suggest format ideas for us to talk over and let me know if you'd like to join in!
update to clarify: When the panel is made up of mostly genuine Blues and one or a few Greens pretending to be Blue, then the judges are all Blue.