You can’t know, and you don’t need to know. I think that’s really missing point of what I said. There is no requirement that Wikileaks or any media only publishes simultaneous dirt on opposing politicians. That would be impossible and can never make sense by the own twisted standards people who complain about Wikileaks are constantly coming up with. To make it possible would mean wikileaks would have to hold back publishing dirt on one until they had enough on the other. Which automatically makes Wikileaks biased in that time period in favor of the one they hold back on. Complaining about Wikileaks publishing dirt makes no sense. The only thing that can make sense is if evidence were ever leaked from a whistleblower in Wikileaks that they had dirt on someone they didn’t leak. Then you’d have evidence of bias. Until then there is none.

You're missing the point.

How do you know that wikileaks is trustworthy? Answer please.

That’s an impossible question for any organization but it’s entirely irrelevant and that’s what you’re missing. The information they leaked was real and important. Where it came from is secondary matter. People only got worked up about it because the information was about their preferred politician. The information could not be disputed, it was correct and not fabricated. But they cared more that dirt was leaked than the fact their politician was dirty. They should examine their principals.