Good answers, in general, are those that have lots of non-partisan facts and analyses, and are clear in their use of partisanship when stitching them into a coherent narrative. By and large, to the extent that fact-laden and coherent answers that actually deal with the asked question should (and I think are) be voted up.
Questions need to elicit facts. If assumptions and partisan readings are pulled out as such, I think its ok - its giving a context in which something should be answered. What needs to be non-partisan, imho, is the desired criteria for an answer.
Imagine the following: (And please note - I most assuredly do not watch Fox News, CNN, or MSNBC!)
Q: Is the US media biased?
As a devoted follower of [Fox | CNN | MSNBC ], I regularly hear complaints that my network is hopelessly [right | left] leaning. Personally, I don't see that. [Rachel Maddow | Bill O'Reily] always tell it like it is. They report all the facts, and don't skim over what [the other guy] says.
So, what is the case that [my station] is biased? Is there a statistical analysis that would show this to be the case?
Notice how the partisan context of the question actually affords a means by which the question can be answered. It acknowledges the bias of the question asker, and admittedly, sets me as the contrarian up to know I have to be really solid, if I'm going to refute it.
The question can be asked an answered with a proposed bias as well:
Q: Is [Fox News | MSNBC] [right | left] biased?
So, what is the case that [my station] is biased? Is there a statistical analysis that would show this to be the case?
A: According to the [Insert Think Tank here], [News Org] is rather [left | right.]
Take, for example, [MSNBC uses the term 'anti-choice' as opposed to 'pro-life' x% of the time. | Fox News is 58% more likely to use the words 'radical left' than 'extreme right' in regular commentary].
Yes, you can leave out the perceived bias, or you can include it. Either way, the onus is on the answerer to use more objective reasoning to either support or attack the claim, using facts, not opinions.