A couple years ago, I tried to edit a page about the economist Deidre McCloskey to add some information about a campaign McCloskey had helped organize in the early aughts to attack & discredit the sex researcher Michael Bailey. McCloskey has tried to cultivate a pro-free speech libertarian image, so I was particularly alarmed when I read a thorough accounting of the Bailey affair in a journal article by Alice Dreger.[0] In fact, I had met McCloskey after the Bailey incident, and knew nothing about it based on the excessively mild portrayal in the Wikipedia article.
I tried to edit the page with a more accurate description: namely, that McCloskey attempted to have Bailey fired from Northwestern for violating "research ethics" and tried to have his license to practice psychology revoked in Illinois. Those facts seemed relevant to me, especially about someone who claims to be libertarian or "Classical Liberal." Wikipedia editors did not think so. The change was reverted almost immediately, even despite my citation of a high-quality source - much higher quality than the journalism garbage backing up many of the claims made on Wikipedia, yada yada. I eventually gave up after realizing one of the editors was on a moral crusade to suppress this piece of information, and none of the other editors were going to question her bias.
I imagine the same thing happens on thousands of other politically sensitive pages.
[0]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170124/