Essay: Best Practices
It shouldn't be controversial to say this, but editors and even administrators can sometimes exhibit bias. Of course, not all of them will, but it is important to acknowledge that assuming good faith in every opposing party may not always be realistic, especially when there is clear evidence of the contrary.
The key to navigating these situations may lie in keeping the discussion centered around Wikipedia's guidelines, policies, and content rather than getting caught up in personal attacks. When dealing with editors you perceive as stubborn or acting in bad faith, it's important to detach emotionally and recognize that anger and reasonable frustration only clouds your judgment. This is why you need to remain emotionally neutral and remind yourself that your goal is to improve Wikipedia's content, not to "win" a personal battle. You should also be open to finding a truly impartial and neutral judge—someone who can evaluate edits without allowing their own prejudices or biases to influence their decision. This kind of unbiased mediation is invaluable for the integrity of Wikipedia but may take a while to eventually find that person and not instantly. If your edits are rejected by an administrator whom you believe as biased or corrupt, it often reflects more on the current state of Wikipedia than on its potential for fairness and accuracy in the future. But what's crucial is that you put forth your best effort with realistic hope.
A meaningful test of Wikipedia's state is its ability to accept a true and verified fact, even when it is opposed by others for reasons that can be attributed more to bias than to genuine grounds for removal like notability, neutrality, redundancy or verifiability purposes. However, this does require you to genuinely do your best. It's essential not to insult others, escalate conflicts, or focus on the character of those involved rather than on the facts and logic of the edits. Remember, Wikipedia is not a courtroom where disputes are won without consensus. It is a collaborative platform where both biased and unbiased editors coexist. When disagreements can't be resolved, it may be helpful to go to Dispute Resolution Noticeboard. In case, that doesn't pan out then you can progress to Arbitration Committee (ArbCom) but only if absolutely necessary.
Hence a good personal policy that an editor should have, is to focus on the facts, be persistent but respectful, make evidence and policy based arguments and seek out neutral perspectives. This ensures you contribute to a community that values cooperation over conflict and knowledge over personal bias. Even when the process seems imperfect, one's commitment to integrity and also collaboration will ensure Wikipedia has the best chance for eventually being a truly informative Wikipedia without bias and emotional prejudice.