Comment by zahlman
On many occasions, right-wing Internet acquaintances have given me a link to a story in a conservative news source; I would try to look up other coverage with a search engine, and I would find exclusively conservative sources discussing what happened, even though it was clearly verifiable fact that the the thing in question had in fact happened.
During the Rittenhouse trial, I watched trial coverage live, then evaluated what various news outlets were saying about what happened. Unironically, Fox News was objectively far more truthful and accurate than every left-wing source. I caught left-wing sources trying to push disproven and dubious narratives - in particular, the "taking an illegal firearm across state lines" bit - long after anyone had an excuse, even after the basic issues with that story had already been debunked by other left-wing sources. Shortly after the verdict dropped, Al Jazeera Plus put out an absurd, naked propaganda piece trying to paint the DA as a hero unjustly thwarted, with imagery showing complete ignorance to and/or resistance of the proven facts of the case.
(As a reminder: this is a DA who didn't check a firearm personally before pointing it at the jury, in order to try to make a ridiculous point about how Rittenhouse might possibly have been holding the weapon, while clearly having no actual idea how to hold and aim it properly. Who then made a closing statement baldly asserting falsehoods about the basics of how firearms work that had been disproved immediately prior. Who had previously made repeated, blatant attempts to violate Rittenhouse's Fifth Amendment rights and introduce evidence that had been very clearly excluded from consideration in pre-trial hearings.)
I have witnessed supposedly respected, mainstream sources (with a rarely acknowledged left-wing bias and an axe to grind) smear people I've personally met, and movements and groups that include people I personally know and care about (especially movements that have nothing to do with the traditional left-right axis but which certain leftists have decided to label as "right-wing" for their own reasons).
The bias built in to Wikipedia's "reliable sources" policy is self-reinforcing. You can't get conservative sources added even if what they're saying is provably true, or "liberal" (an absurd abuse of the term, but that's the American jargon now) sources excluded even if what they're saying is provably false, because a) the latter agree with each other; b) a new source needs vetting, which generally involves agreeing with existing sources; c) there is no objective standard for accuracy or reliability.
You present your comment as though you imagine that "sources that aren't explicitly conservative" are, thereby, not also "overtly biased". A lot of people seem to believe this, but it's not at all true. The fact that you frame this in terms of "defending positions" is also telling, for me.
See also: https://slatestarcodex.com/2017/05/01/neutral-vs-conservativ...
You actually highlight the problem very well. Any group of people can make their own websites, publish their own papers, produce their own films, cross-refencing each other all along the way, thereby creating the illusion their their alternate reality, though largely fabricated, is as true as the real world we all live in. But it isn't. The "facts" within that sphere are only supported by other "facts" within that same sphere, and they fail to connect to the larger, long-standing and global web of data, research and opinion that are far more diverse, well-documented and debated. And by failing to connect, or only tenuously connecting, to the larger conversation they are rendered irrelevant, except for their use as a weapon towards personal or political ends.