It should come as no surprise by now to anyone that I actually operate multiple accounts on the popular game/forum NationStates, which is actually a common practice. As a general rule, I operate those accounts in dichotomous pairs: a catholic theocracy versus a thoroughly agnostic society, for an example. There was also a monarchy versus a communist bloc, and those two pairs were about it as far as political experimentation went - there was a stand-alone corporatocracy that became scary because I demonstrated that I can set all moral understanding aside when putting down economic arguments, so I "retired it".
I've played some alt-history, some alt-species, and all around the spectrum of technology levels, but as far as political experiments went, it was limited to the four countries. As far as political discussion in out-of-character contexts went, there were actually only two I used - the first pair mentioned.
San Benedict e San Francesco was the Catholic Theocracy, which actually turned into something of a liberitarian's wet dream as my gut reduced government involvement. By contrast, Ivory Record was a Sci-Fi nation, built entirely on two concepts - meritocratic demarchy, and Ipsa scientia poestas est. As a result, the pair formed natural counterparts without my direction, and when they interacted through Ivory's past-tech analogues, their behaviour was usually cordial.
More often than not, however, I entertained the idea of using them both to make similar arguments in the out-of-character sections of the forum. SBSF's signature gave an identity as a "proto-seminarian", a term that I never explained, but was mostly intended to demonstrate a strong enthusiasm for theology - something I backed up by keeping the Catechism and the ESV sitting on the desk, ready for quick reference in arguments. Ivory, on the other hand, was both my "main persona", in that it contained the link to this page and less vague references to my identity, but also because it was the one I used the most.
Strictly speaking, I never intended the pair to operate in the same threads, or even for both to operate OOC at all (generally, I favoured Ivory for that role, since it made the most sense). However, in a few threads where both participated, I noticed a peculiar effect.
Ivory and SBSF usually hold similar, if not identical, positions, particularly if the issue is about a moral standard of some sort that's not related to sexuality. However, a peculiar effect began to emerge. Both SBSF and Ivory had audiences - regular occurrences of being "quoted for truth" or the ever-famous non-constructive forum technique of quoting a post with the text "^this" beneath it, so that the carat points to the original post, by way of showing agreement. However, these audience were almost entirely mutually exclusive, even in contexts where they both agreed completely.
I couldn't understand the need for it. Ivory's user's Christianity is an open secret - it's not referred to on the profile or in the signature but it is mentioned several times in many places - usually to counter the "well, what would an atheist know about theology/morality/Jeebus" argument, but also to come to the defence of Hapless Highschool Student A who used theology to make unpopular points, and accordingly is getting pounded on for being Christian, usually by Ivory's flagship audience. Because of that, I couldn't quite chalk up the opinion split to a simple pro-/anti- Christianity/Spirituality phenomenon, and because the positions were usually the same, I couldn't find the reason for the difference.
Then it occurred to me - the objections out-of-character entirely had to do with the in-character statistics! Conservatives were attracted to SBSF because its in-game mechanics made it inherently conservative (even if it was a remarkably liberal theocracy), whereas Ivory showed up as Liberal (though, by Euro standards, it was pretty well mired in the centre). So conservatives agreed with SBSF on principle, liberals agreed with Ivory on principle, and neither must have read the other's arguments, or at least, were ignoring them.
It's strange to be that confirmation bias is so strong you can ignore the other side agreeing with you. In fact, I brought this up to an amigo the other day - there is a moment, when someone you vehemently disagree with on other issues suddenly agrees with you, that you question if you were even right.