I noticed of many bias comments and voting , they go for emotions not for reasons and explanations, if they are convinced about something just refused or vote for close. they dont explain why they downvote it. even if you want to downvote this question , explain the reason so I make it better.
Politics have bias. The best thing you can do to combat the bias is to down vote answers that are unsourced or do not directly answer the question asked. If the question being asked is not objective or not asking for information but just seeking opinions that back up their belief, then down vote and vote to close that question(or answer) even if the bias is one you agree with.
I find it funny that most of the Right Leaning posters to this site think I am a liberal and most of the Left leaning posters think I am Corporate statist. I will upvote good answers that are against my personal belief's if they are a good representation of the facts presented in a way that does not conflate opinion. I do not down vote opinions I disagree with if the opinions are an appropriate response and they are framed so it is clear that the response is opinion and not presented as a fact.
However even if I think that the opinion is right, if it is presented as fact, or not an appropriate response to a proper question, then I will down vote it.
I also do my best to avoid bickering about the positions in comments. My comments are not about the right or wrong of the post most of the time, but rather I comment on the quality of the question or answer. The intent is to improve the post so that it does meet the SE guidelines. One of the big risks I see for this site is that we tolerate too many bad subjective questions, and too many answers that are non-answers.
The way to correct this issue is to downvote and flag the offenders. Explain in comments how they can do better. If possible with out a heroic effort, Edit the post into something that is objective and meets SE Standards. That does not mean change the obvious slant in a post, that is just going to trigger an edit war. But when someone asks a question that is at its core a good question, but phrased poorly edit it to bring it up to standards. When someone posts a decent answer improve it with references where you can.
These things will help improve the site. We have a serious broken window problem and the only way we can fix it is to stop contributing to the broken windows ourselves, and to let people know it is not ok to break windows in our neighborhood any more.