The concept of triangulation used to mean politicians looked at the political landscape and positioned themselves on the field to advance their policy goals.  The worsening development, facilitated by mass media and social media, is the attempt to manipulate the landscape.  That’s where we start to think of the Overton Window, shifting the range of positions people think are acceptable, and it’s what we see here:

I think Jonah misunderstands (or pretends to misunderstand) what’s going on, here.  Democrats (among whom I count the mainstream media) promoted Trump and are doing everything they can to paint him as a monster because the worse they make him out to be the worse they can be.  That’s why Barr is right that, in a binary decision, Trump is preferable, and not seeing it may be why Jonah has taken his wise reservations about Trump so far as to be an error.