An issue-focused wiki portal is one that primarily exists to gather multiple point of view (MPOV) on neutrally stated issues, and encourages participation by diverse groups with very different views. Their use of StructuredData lets them support a wider range of participants than conventional wikis which often have troll wars between participants.
Many issue-focused wikis use the issue/position/argument form which allows positions of many parties and major groups to co-exist on the same page without overwriting or censoring each other. More Perfect, DKosopedia, uk.openingpolitics.org and openpolitics.ca (which has by far the largest number of pages in this form so far). In addition a few technologically focused projects like let.sysops.be use this format.
Other formats used for issue-focused wiki and online deliberation are analyzed at openpolitics.ca including those from debatepoint.com, Wikocracy, etc.. By far the most mature analytic approach is the dkosopedia.com Frametank approach which often involves staging a questionable claim through several namespaces to neutralize conclusions, ultimately trying to reframe it into a form that accomodates more debate.