Justice? Yeah, Justice Because of Democracy

An arbiter shouldn't have any biased because he or she should be trying to help both sides. But how do we know that the judges that help to dispute issues are really impartial? How do we know that they are treating the cases with objectivity? For all I know, a judge might feel disdain or any other negative emotion for homosexuals or women or whatever, and that feeling will have no matter what an impact on the judges decision. Isn't that so? The people that the judges don't like might have a substantiated case, but the judge could decide to exculpate the person they like best. If this occurred, many people would then be vindicated. Good thing we live in a democracy and things like this are not allowed to happen. I mean they happen sometimes because we are not perfect. Democracy is not a perfect government systme; it has just proven to be the best one that exists.