But to fact check a number of more complex issues requires a lot of knowledge in a field, and if the possessors of that knowledge are not trusted by people (or if there are actual competing interpretations) then all we'll end up with is more echoing and ignoring.
I think that the most egregious problem of modern democratic debate sits behind each screen that reads this. What I mean by that is the propensity to not so much debunk sources, but to debunk sources that do not belong to the echo chamber that the reader belongs to.
It becomes, in essense, a battle of sources. Fox News is one echo chamber. MSNBC is another. The pundits of the reader's own echo chamber are upstanding researchers and historians, and the pundits of the other echo chamber are charlatans and hacks.
There is also the thing that economy is removed from sciences, in that replication is not required to publish theories about anything, and statistical analysis is more about finding what you want than going out there and finding what the numbers actually say. So, you have the battle of the Nobel Prize laureates - who to believe? A guy like Krugman or a guy like Hayek? Depending on your echo chamber, the answer is readily availible.
But.... That's not critical thought. Those are appeals to authority, which are as far from critical thinking as you can get. It is in fact a logical fallacy in its own right. The only way to arrive at a truth is through experiment and replication.
But none of us here do it. I don't, of course. I'll be the first to admit that. I tend to post links from places that I like, and not so much from places that I dislike. Critical thinking is hard. It requires that sources are not
only evaluated based on the acronyms of academic titles attached to a person's name and bias - but it also requires also the realisation that in many, many fields we that post here just don't know what we're talking about - be it economy, law, science, history. Each of us have a slightly different level in things. We know more of one thing, and less of another.
But few of us, and that includes me, are too keen to improve our thinking by admitting both bias and lack of knowledge. And I think that's true for most people, and so we fall to appeals to authority to bolster our own claims, and we do this more out of personal bias than anything else.