I have a problem with this specific meta question because it seems to suggest that there are people who are not biased or viewpoints which are not biased. I don't think such people or viewpoints can exist for political questions.
I think what you really mean are people who are asking rhetorical questions because they already know the answer. Those people who are not really asking questions, but trying to spread their worldview. In this case the "promotes or discredits a specific political cause" flag is exactly the thing to ask for, but for all other cases I do not see any benefit for the following reasons.
First, the political landscape is vast and very different in different cultures, so what exactly do you mean with bias? A french anarchist, a German environmentalist, an US libertarian, a Zulu from the Inkatha party, an Israeli soldier, an Indian BJP party member, a Tunisian Muslim? Everyone will give you pretty good reasons for the worldview they have. Even the average Joe is pretty different for countries and cultures, so what should the benchmark be?
For all intents and purposes the best you can do to be impartial is citing only facts and documents. But even they have been selected from a pool of possible documents, they can be interpreted in different ways, (and yes, it is possible that several viewpoints can come to different valid(!) conclusions), you cannot read minds and you don't know the exact, often confidential, reasons for some decisions, so even with best effort you cannot make more than an educated guess.
So what if the "poor" answer is actually right or at least plausible, but violates your own bias? May I remind the threads where left-leaning people are complaining about right-leaning bias here and vice versa? If Politics.SE wants to be "unbiased" as best as possible, your question is, if taken word-for-word, a kind of oxymoron.