What is the extent of the validity of community polls?

This poll operates like a wiki: feel free to update its summary and, if applicable, add a new, better option to the poll itself.

As you know, the content of our Community Manifesto is based on results of community polls (i.e. polls that are only open to registered members and not to anonymous visitors).
However, it may happen that users come and go. Users who have voted in old polls may no longer be active. The external situation may change so that the context of a specific poll may no longer be the same. Also, it may happen that two different polls on very similar topics may give contradictory results. If so, which poll should prevail? And there may be other causes that may invalidate some community polls.

Currently, we have no existing policy regarding the extent of the validity of community polls. This poll aims to fill that gap. Use the Opinion post to discuss this, and add options to the poll accordingly.

Listing in manifesto:
http://minguo.info/usa/manifesto/polls

Choice Blog entries Score votes Maximum score
90 % Results from member polls are valid until superseded by a newer poll on the same topic. 0 18 2 20
80 % Disputes on the interpretation of the results of a poll can be settle with a new ad-hoc poll. 0 16 2 20
55 % The poll with the most votes has precedence over other polls. 0 11 2 20