All human sources of information are biased. That's why we have democracy - to duke it out in a market of ideas and find some common denominator that somehow summarizes people's opinions. True, this system is not perfect. But removing inputs would not make it more perfect - unless by some magic you imagine that the only inputs left are optimal ones. But finding the optimal ones is the problem with started with! If we knew that, there would be no need for the rest - it's because there's no definite obvious way to know what is right is that we have democracy, otherwise we'd just have one law: "always do what's right" and that's it, no need for congress, elections, etc.