It can get polarized within the mainstream, too.

https://en.wikipedia.org/wiki/Talk:List_of_U.S._executive_br...

In your opinion, what is some misinformation on RFK's page?

Have you read the discussions on the talk page?

If your concern has not been extensively discussed, have you raised it on said page?

Here is a link: https://en.wikipedia.org/wiki/Talk:Robert_F._Kennedy_Jr.

You might enjoy this story: https://www.tracingwoodgrains.com/p/reliable-sources-how-wik...

The short version is that you can make Wikipedia report the way you want, but you need to be strategic about it. Wikipedia reports information from "reliable sources", so instead of editing the information directly, you need to insist that the sources that agree with you are reliable and the sources that don't agree with you are unreliable. If you succeed at this, then getting the information you want into Wikipedia is just straightforward following of Wikipedia's written policy.

Wikipedia is free for everyone to edit. The policies are strongly aligned with the pursuit of truth. Both parties can have truths in their favour, if editors are in a left wing bubble they may just be more exposed to truths from a left perspective. Here's where you can help! If you identify bias, feel free to remove charged language, and add new ideas with reliable citations. Here's a list of sources considered reliable: https://en.wikipedia.org/wiki/Wikipedia%3AReliable_sources%2...

Extensive discussions of the decision making process for each source is documented in this list.

There's always Conservapedia if Wikipedia isn't working for you!