It calls out what they see as a liberal trend of "factiness", that is, the feeling of knowledge without being able to actually use that knowledge to predict the future.

It mentioned other liberal-aligned media that creates this feeling of knowledge, such as ted talks and "NPR-style neuroscience".

Basically, it's calling out the liberal trend to presume that the facts are on their side and then be wrong about it. Presumably due to a failure in their epistemology, how they gather and sort data about the world.

There are a couple of other minor points and rhetorical points, like equating liberals "factiness" to the hated outgroup's "truthiness". But that's the general thrust.

What I took away from the article is that just as one may support an argument with 'truthiness' i.e. I feel it in my gut but have no facts or the facts oppose my argument, there may be a thing called 'factiness' where all the facts support your argument, but it misses the truth that others see and feel and that can't be quantified with traditional facts.

It is a good reminder that just as one should be wary of arguments supported only by truthiness, one should also be wary of arguments supported only by factiness.

I think he is trying to reassure other liberals that they are still better people than all those racist fascists that voted for Trump.

He wrote it at 2:41 am, Nov 9th.

People are just trying to understand what happened and for some this involves exercises in thinking out loud.