Columnists often project their own interests and views onto voters. But this, from Andrew Sullivan, is so wildly detached from the lived reality of anyone involved in or reporting on, or in many cases voting in, the 2018 election. 
You can argue that tribalism is a defining force - or the defining force - in American politics without making the kind of claim that suggests you’ve never talked to an undecided voter or visited a competitive congressional district or state.
(Re-reading it, the rhetorical choice to group health care — a life-or-death or bankruptcy-threatening issue for millions — with relatively abstract debates about “norms” and the executive branch is probably the most revealing part.)
